For a portable electronic device safe with a digital keypad and steel body, I would start with the SentrySafe P021E. The Master Lock 5900D is a better fit for carrying a phone near water or keeping it accessible for charging while locked, while the SentrySafe P008E-BL offers a compact keypad option with two user codes. The main tradeoffs are clear: the P021E gives you more room and a backup key, the Master Lock prioritizes water resistance and cable access, and the blue SentrySafe keeps the footprint modest at the cost of water protection and capacity.
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These are small portable safes for limiting casual access to phones and other valuables; none should be treated as a substitute for a full-size home safe or a guarantee against determined theft. I rank them by how well their size, locking method, portability, and practical features suit different electronic-device use cases.
Key Takeaways
- SentrySafe P021E: My overall pick for buyers who want a digital keypad, steel construction, backup key, and the most stated capacity in this group.
- Master Lock 5900D: The only option here described as water resistant, with a port for charging cables or earbuds while the safe is locked.
- SentrySafe P008E-BL: A compact steel choice with two programmable user codes, though its 0.08-cubic-foot capacity matches the smaller Master Lock.
- The P021E and P008E-BL need batteries for keypad operation; the supplied product details specify four AA batteries for the P021E but do not list the battery type for the P008E-BL.
- All three include a way to tether the safe, but a cable can limit convenient removal rather than make the safe theft-proof.
| SentrySafe Portable Black Safe Box with Digital Keypad Lock – Small Steel Travel Safe with Carrying Handle (0.21 cu ft, 4.4 x 13 x 10 in) |  | Best Overall | Model: P021E | Capacity: 0.21 cubic feet | Exterior dimensions: 13 x 10 x 4.4 inches | VIEW LATEST PRICE | See Our Full Breakdown |
| Master Lock 5900D Portable Travel Safe with Cable |  | Best for Water-Exposed Settings | Model: 5900D | Capacity: 0.08 cubic feet | Exterior dimensions: 2.25 x 9.53 x 4.92 inches | VIEW LATEST PRICE | See Our Full Breakdown |
| SentrySafe Small Blue Safe with Digital Keypad |  | Best Compact Keypad Safe | Model: P008E-BL | Capacity: 0.08 cubic feet | Exterior dimensions: 2.9 x 10.0 x 7.9 inches | VIEW LATEST PRICE | See Our Full Breakdown |
| portable electronic device safe | Model | Capacity | Exterior dimensions | Interior dimensions |
|---|---|---|---|---|
| SentrySafe Portable Black Safe | P021E | 0.21 cubic feet | 13 x 10 x 4.4 inches | 12 x 8.9 x 4.3 inches |
| Master Lock 5900D Portable Tra | 5900D | 0.08 cubic feet | 2.25 x 9.53 x 4.92 inches | 1.25 x 8.13 x 3.5 inches |
| SentrySafe Small Blue Safe wit | P008E-BL | 0.08 cubic feet | 2.9 x 10.0 x 7.9 inches | 1.9 x 9.8 x 7.1 inches |
More Details on Our Top Picks
SentrySafe Portable Black Safe Box with Digital Keypad Lock – Small Steel Travel Safe with Carrying Handle (0.21 cu ft, 4.4 x 13 x 10 in)
The SentrySafe P021E makes the strongest general-purpose case in this lineup because it offers substantially more stated capacity than either 0.08-cubic-foot alternative. At 0.21 cubic feet, its interior is listed as 12 by 8.9 by 4.3 inches, giving buyers more flexibility to store a phone alongside a passport, cash, or other small valuables. The built-in handle also makes it straightforward to move between a suitcase, car, and room.
Its digital keypad with backup key gives it a different access setup from the Master Lock’s four-digit combination. That may suit a buyer who wants a programmable code but a backup way in if keypad access becomes inconvenient. It does require four AA batteries, and its product details do not list water resistance. Compared with the Master Lock, the P021E offers more room but gives up the charging port and the stated water-resistant construction. Compared with the blue P008E-BL, it is larger and includes a backup key, but it is also heavier and less discreet in a tightly packed bag.
The steel body and included tethering cable can help limit opportunistic access when the safe is attached to a fixed object, though the cable is not a substitute for a robust permanent installation. I would choose this model for trips where capacity and keypad convenience matter more than minimizing bulk or keeping the contents accessible while locked. Its drawbacks are its modest overall capacity for anything beyond small items, battery upkeep, and lack of water resistance.
Pros:- Larger 0.21-cubic-foot capacity than either other pick
- Digital keypad with backup key
- Steel construction, carrying handle, and soft interior cushioning
- Includes a tethering cable
Cons:- Requires four AA batteries for keypad operation
- Not water resistant
- Still too small for larger electronics or bulky accessories
Best for: Travelers who want a keypad safe with room for a phone, passport, and a few small valuables, and who value a backup key.
Not ideal for: Buyers who need water resistance, a very slim profile, or a charging port that remains accessible while the safe is locked.
- Model:P021E
- Capacity:0.21 cubic feet
- Exterior dimensions:13 x 10 x 4.4 inches
- Interior dimensions:12 x 8.9 x 4.3 inches
- Weight:4.6 pounds
- Lock:Digital keypad with backup key
- Material:Alloy steel
- Power:Four AA alkaline batteries
Our verdict“I recommend the P021E as the most versatile choice here for buyers who prioritize capacity and keypad access over water resistance and compactness.”
Master Lock 5900D Portable Travel Safe with Cable
The Master Lock 5900D is the most device-specific pick when the safe may be used around splashes or when the owner wants a phone to remain connected while stored. Its water-resistant construction and foam-lined interior provide a different sort of everyday reassurance than the steel keypad safes, and the port lets a charging cable or earbuds pass through while the safe stays closed. That combination can suit a pool day or shared workspace where a device needs to stay protected from casual handling but remain usable.
Those features come with a firm capacity limit. The interior measures 1.25 by 8.13 by 3.5 inches and totals 0.08 cubic feet, so it is best matched to a phone and a few flat essentials rather than a larger bundle of travel items. The P021E is the clear choice if you want more room or a backup key; the P008E-BL offers a keypad and steel body in a similarly compact class. The 5900D instead trades those attributes for water resistance and access to a cable while locked.
Its four-digit combination avoids the AA-battery requirement stated for the P021E, while the cable can secure the safe to a fixed object or serve as a carrying handle. I would not interpret its water-resistant description as waterproof protection, and its multi-material construction is a different proposition from the steel bodies of both SentrySafe models. Choose it for the charging port and splash-conscious use; skip it if interior height, maximum capacity, or steel construction is your priority.
Pros:- Water-resistant construction with a foam-lined interior
- Port allows charging or earbuds access while locked
- Four-digit combination lock
- Cable can tether the safe or act as a handle
Cons:- Small 0.08-cubic-foot capacity and shallow interior
- Water resistance does not mean waterproof
- Multi-material body differs from the steel construction of the SentrySafe picks
Best for: People who want to keep a phone in a compact safe around splashes and need to pass a charging or earbud cable through while locked.
Not ideal for: Buyers who need room for multiple devices, a taller interior, a steel body, or confidence that the safe is waterproof.
- Model:5900D
- Capacity:0.08 cubic feet
- Exterior dimensions:2.25 x 9.53 x 4.92 inches
- Interior dimensions:1.25 x 8.13 x 3.5 inches
- Weight:0.71 kg
- Lock:Four-digit combination
- Material:Multi-material construction
- Water protection:Water resistant; not described as waterproof
Our verdict“I would choose the 5900D when water resistance and a cable-access port matter more than capacity or a steel body.”
SentrySafe Small Blue Safe with Digital Keypad
The SentrySafe P008E-BL suits buyers who want a small steel safe with keypad access and two user codes. That second code is its clearest distinction from the larger P021E, whose listed features include a digital keypad and backup key. For a household or travel companion arrangement where two people need their own access codes, the blue model offers a useful setup in a compact package.
Capacity is the compromise: at 0.08 cubic feet, it shares the Master Lock’s stated volume and is far below the P021E. The listed interior dimensions of 1.9 by 9.8 by 7.1 inches suggest a shape that may fit a phone and some slim items, but buyers should compare their device and case measurements before choosing. It includes a steel tethering cable, and its 3.7-pound weight is lower than the P021E’s listed 4.6 pounds. Unlike the Master Lock, however, it is not water resistant and has no described charging port.
This model has a steel body and electronic keypad, making it a straightforward choice for keeping small valuables in a backpack, luggage, or desk drawer. The product details do not specify its battery type, so I would check the included documentation before travel rather than assume the same four-AA arrangement as the P021E. I rank it behind the other two because it has neither the P021E’s greater capacity and backup key nor the Master Lock’s moisture-oriented features. Its appeal is focused: a compact keypad safe with two user codes.
Pros:- Electronic keypad supports two user codes
- Steel construction in a compact package
- Includes a steel tethering cable
- Lighter than the P021E based on the listed specifications
Cons:- Small 0.08-cubic-foot capacity
- Not water resistant
- Battery type is not specified in the supplied product details
Best for: Buyers who want a compact steel safe with keypad entry and separate programmable codes for two users.
Not ideal for: People who need water resistance, charging access while locked, or enough room for more than a phone and a few small items.
- Model:P008E-BL
- Capacity:0.08 cubic feet
- Exterior dimensions:2.9 x 10.0 x 7.9 inches
- Interior dimensions:1.9 x 9.8 x 7.1 inches
- Weight:3.7 pounds
- Lock:Electronic keypad
- User codes:Two
- Material:Alloy steel
Our verdict“I recommend the P008E-BL for two-user keypad access in a compact steel safe, provided its limited capacity and lack of water resistance fit your needs.”
How We Picked
I compared the three products as portable electronic device safes, focusing on what changes the buying decision: the available interior space, lock and access method, portability, tethering, and any stated protection from moisture. I gave the P021E the top overall position because its listed 0.21-cubic-foot capacity is larger than the two 0.08-cubic-foot alternatives, and it pairs a digital keypad with a backup key. That makes it the most flexible fit for a phone plus a few small travel items, though its size and battery dependence are real tradeoffs.
The Master Lock earns a distinct role because it adds water-resistant construction and a cable-access port. Those features are more relevant to a phone used at a pool, beach, or shared workspace than an extra keypad code would be. Its interior is notably shallow, and water resistance does not mean waterproof. I placed the P008E-BL third because it offers a steel body and two user codes in a compact package, but its listed capacity is small and it lacks the Master Lock’s water-resistant design and charging access.
I used the supplied descriptions and specifications, rather than treating any of these compact products as high-security vaults. The ratings reflect stated features and tradeoffs for everyday portable storage. Actual fit depends on device dimensions and any case attached, so buyers should compare the interior measurements with the items they intend to store.
| portable electronic device safe | Lock | Material |
|---|---|---|
| SentrySafe Portable Black Safe | Digital keypad with backup key | Alloy steel |
| Master Lock 5900D Portable Tra | Four-digit combination | Multi-material construction |
| SentrySafe Small Blue Safe wit | Electronic keypad | Alloy steel |
Factors to Consider When Choosing Portable Electronic Device Safes
I would choose a portable device safe by matching its interior to the device, then deciding which access and protection features matter in the setting where it will be used.Measure the device and the safe interior
Start with the device’s full dimensions, including its case, then compare those measurements with the safe’s listed interior. Capacity alone can mislead: two safes with the same cubic footage can have different shapes. The P021E lists a 4.3-inch interior height and 0.21 cubic feet, giving it more room for a phone and flat travel items than either 0.08-cubic-foot option. The Master Lock’s 1.25-inch interior height favors flatter contents. The P008E-BL lists a 1.9-inch interior height, but its internal footprint differs. Allow room to place and remove the device without forcing the lid closed.
Choose a lock style you can manage
The P021E and P008E-BL use electronic keypads; the P021E also lists a backup key, while the P008E-BL supports two user codes. The Master Lock uses a four-digit combination and does not list a battery requirement. If you prefer keypad entry, account for the batteries: the P021E specifies four AA alkaline cells, and the supplied P008E-BL details do not identify its battery type. Keep access information available separately from the safe, and check the product instructions for its recovery procedure before a trip.
Treat tethering as a deterrent
Each pick includes a cable intended to connect the safe to a fixed object. Tethering can make it harder for someone to simply pick up the box, particularly in a hotel room, dorm, or shared office. It does not make the safe theft-proof, and the strength of the anchor point matters. The P021E’s built-in handle supports carrying between locations; the Master Lock’s cable can also act as a handle. Consider whether the cable’s length and your available anchor points suit the places where you expect to use the safe.
Match moisture protection to the setting
Only the Master Lock is described as water resistant. That makes it the strongest fit here for settings where splashes are a concern, but the description does not claim waterproof protection or give a submersion rating. Both SentrySafe models are listed as not water resistant. For any option, keep the safe away from standing water and check the manufacturer’s guidance if moisture protection is central to your use. The foam lining in the Master Lock can cushion contents, but it does not change that limit.
Decide whether the device should stay connected
The 5900D has a port for charging cables or earbuds while locked, a feature neither SentrySafe description lists. This is useful if you want to keep a phone in the safe while charging or listening, but the opening also means a cable needs to pass through the case. If you would rather store the device fully enclosed and disconnected, the P021E or P008E-BL may be a better match. For either approach, check that the cable and connector fit the intended port and that the device sits comfortably inside.
Keep expectations in line with a portable safe
These products are compact containers for limiting casual access to small valuables. Their portability and included cables can help with everyday travel storage, but the supplied details do not establish a particular theft-resistance rating. If you need protection for several devices, large electronics, or valuables that require stronger long-term security, these small formats may not meet the job. For this lineup, the P021E offers the most stated capacity; the other two are better chosen for their distinct access or moisture features.
Frequently Asked Questions
Which of these safes has the most room for a phone and travel essentials?
The SentrySafe P021E has the largest listed capacity at 0.21 cubic feet, compared with 0.08 cubic feet for both the Master Lock 5900D and SentrySafe P008E-BL. Its 12 by 8.9 by 4.3-inch interior also offers more flexibility for a phone plus a passport or other small items. Check the actual device dimensions against the interior before buying, especially if the phone has a bulky case.
Which portable safe is the better choice around water?
The Master Lock 5900D is the only product in this group described as water resistant, so it is the one I would consider for splash-prone settings. Its product description does not say that it is waterproof, and it does not provide a submersion rating. The P021E and P008E-BL are both listed as not water resistant, so keep them away from moisture.
Can I charge my phone while it is inside the safe?
The Master Lock 5900D has a port designed to allow charging cables or earbuds to pass through while the safe is locked. The supplied descriptions for the two SentrySafe models do not list a comparable port. Before relying on the feature, confirm your cable connector fits and that your phone can sit inside without pressure on the cable or lid.
Do the keypad models need batteries?
The SentrySafe P021E specifies four AA alkaline batteries for its digital keypad. The P008E-BL also uses an electronic keypad, but the supplied product details do not state its battery type or count. The Master Lock uses a four-digit combination and its listed details do not specify a battery requirement. Check the manufacturer’s instructions for operating and backup access details before travel.
Do the included cables make these safes theft-proof?
No. A tethering cable can make a safe harder to carry away quickly when it is attached to a suitable fixed object, but it is not a guarantee against theft or a replacement for a properly installed high-security safe. The anchor point and how the cable is used both matter. I would treat the cables as a practical deterrent for casual handling during travel or shared-space use.
Conclusion
I would choose the SentrySafe P021E if I wanted the most room in this group, keypad entry, and a backup key. For a phone that may be near splashes or needs a cable connected while locked, the Master Lock 5900D is the more focused option, provided its shallow interior fits. If two people need separate keypad codes and a compact steel body is the priority, I would look at the SentrySafe P008E-BL. In each case, check the interior dimensions against your device and treat the included tether as a deterrent rather than a guarantee of security.
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