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Master Lock

Master Lock Portable Small Lock Box, Set Your Own Combination Lock Portable Safe, Personal Travel Safe, 5900D, Gunmetal Grey

  • Based on 17,528 reviews
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Availability: In Stock.
Fulfilled by Amazon
Arrives Thursday, May 21
Order within 20 hours and 33 minutes
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Color: Gunmetal Grey


Size: 9.8 x 5.5 x 2.6 inches


Features

  • Small safe is ideal for use as a travel safe or personal safe for protection and security from theft
  • Secure small safe to a fixed object with cable; Portable safe is best used to protect smart phones, passports, cash, and credit cards
  • Set your own four-digit combination portable safe; Ear bud/charging cable access port to conveniently listen to music or charge devices while locked
  • Constructed with a shock absorbing foam, small lock box is designed to be water-resistant
  • Exterior dimensions: 2-1/4 inch H x 9-17/32 inch W x 4-59/64 D; Interior dimensions: 1-1/4 inch H x 8-1/8 inch W x 3-1/2 inch D

Description

The Master Lock 5900D Set Your Own Combination Portable Personal Safe features durable construction made to withstand abuse and is water resistant. The safe measures 2-1/5in (57mm) H x 9-2/5in (23.9cm) W x 5-1/10in (13.1cm) D; and is ideal for recreation, campus, office, travel or leisure use. The safe includes a cable to wrap securely around a fixed object or use as a carrying handle. The Limited Lifetime Warranty provides peace of mind from a brand you know and can trust.

Brand: Master Lock


Product Dimensions: 3.5"D x 9.31"W x 2.25"H


Lock Type: Combination


Color: Gunmetal Grey


Capacity: 0.08 Cubic Feet


Material: Multi


Special Feature: Portable


Mounting Type: Freestanding


Included Components: 1


Item Weight: 0.71 Kilograms


Lock Type: Combination


Additional Features: Portable


Mounting Type: Freestanding


Alarm: Audible


Water Resistance Level: Water Resistant


Smart Home Compatibility: Not Smart Home Compatible


Control Type: Touchpad Control


Item Dimensions D x W x H: 3.5"D x 9.31"W x 2.25"H


Capacity: 0.08 Cubic Feet


Item Weight: 0.71 Kilograms


Chamber Height: 1 Inches


Chamber Width: 8.13 Inches


Chamber Depth: 3.5 Inches


Color: Gunmetal Grey


Material Type: Multi


Brand Name: Master Lock


Included Components: 1


Model Number: 5900D


UPC: 071649147784


Global Trade Identification Number: 84


Manufacturer Warranty Description: One year limited warranty


Manufacturer Part Number: 5900D


Item Type Name: Set Your Own Combination Portable Safe


Manufacturer: Master Lock


Unit Count: 1.0 Count


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Thursday, May 21

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • PayTomorrow Financing
  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Similar Products

Top Amazon Reviews

    • Good quality safe
Color: Gunmetal Grey Size: 9.8 x 5.5 x 2.6 inches
small safe that works great. Strong protection.
Reviewed in the United States on May 10, 2026 by Raymond Kolman
    • Compact, secure, and travel-friendly – A must-have for peace of mind
Color: Gunmetal Grey Size: 9.8 x 5.5 x 2.6 inches
I’ve used the Master lock portable small lock box locally and on 2 trips, Vegas and Cancun, and I can confidently say it’s one of the smartest purchases I’ve made for protecting my valuables. Whether I’m on the go, at the gym, at the beach, or just need a secure place to stash items in my car, this lock box delivers outstanding performance, durability, and peace of mind. The customizable 4-digit combination lock is easy to set and eliminates the hassle of carrying or potentially losing a key. The locking mechanism feels solid and responsive, giving me confidence that once it’s locked, it’s truly secure. It’s strong enough to deter opportunistic theft and gives me assurance when leaving items unattended in public settings. Don’t be fooled by the term "small" — the interior space is very well-designed. I can comfortably fit my phone, passport, small wallet, keys, and even some jewelry with room to spare. The foam lining inside is a thoughtful touch that prevents my items from shifting around or getting scratched. It’s also a good size for securing medication if needed. This lock box truly shines in its versatility: Beach trips: I loop the cable around a beach chair or inside my beach bag. I can swim without constantly worrying about my phone or car keys being stolen. Hotel stays: Not every hotel has an in-room safe, and this box is a great portable alternative. Car security: I’ve used it to store cash or spare keys in my car when I don’t want to carry them into the gym or on a hike. Airbnb or shared living spaces: It adds an extra layer of security for valuables when you're staying somewhere unfamiliar. The included cable loop is extremely handy — it allows you to secure the box to a fixed object like a bed frame, chair, railing, or inside your trunk. It’s coated in plastic to avoid scratches but still strong enough to resist cutting or tampering. The outer shell is made of impact-resistant ABS plastic, and the internal foam padding protects delicate contents from damage. It’s also water-resistant, which is a big plus for beach or outdoor use. It’s not waterproof, so I wouldn’t submerge it, but it can definitely handle splashes and light rain without issue. This is an excellent all-around lock box for anyone who values security, portability, and peace of mind. Whether you’re a traveler, student, athlete, parent, or just someone who wants an extra layer of security in unpredictable environments, this product is a fantastic choice. Pros: Customizable combo lock – no key needed Foam-padded interior to protect contents Water- and impact-resistant exterior Compact but holds a surprising amount Strong cable for tethering to fixed objects Affordable and well-built Cons: Not fireproof or waterproof (but not designed to be) Cable can be a little stiff at first use Would I buy it again? Absolutely. In fact, I’ve already ordered a second one as a gift! ... show more
Reviewed in the United States on May 14, 2025 by JohnAstros
    • Great for holding cash and very small things
Color: Pink Size: 9.8 x 5.5 x 2.6 inches
I began running a business out of my home that, quite often, results in our customers stopping by or meeting me somewhere and paying in cash. As business started picking up and I was holding more and more cash at any given time, it occurred to me that the adolescents in my house might not have quite learned the true meaning of a "business" and the ethics that are involved in distinguishing the difference between "Mom and Dad's money" and the "Business's money." Yeah, I know, it's terrible not to be able to trust your own kids, but what can you do? I gave it 4 stars because it functions just fine, and it's nice and compact so you can tuck it just about anywhere. It's a good little safe, and it has a built in security cord so you can tether it to something anchored if you needed to as well. The only reason I took a star off is because the rubber flap that covers up the dial is awkward to hold open when you are trying to work the combination lock, and, honestly, I don't like the color pink. And it is Pepto Bismol pink, no doubt. But I do support Breast Cancer Awareness, and if even a dollar of my purchase went there, then pink it shall be! Plus, for some reason, the pink Breast Cancer Awareness safe was less expensive than the basic black one... Can't figure that math out, but it works for me! ... show more
Reviewed in the United States on March 31, 2014 by Jennifer
    • Strong and safe for valuables!
Color: Gunmetal Grey Size: 9.8 x 5.5 x 2.6 inches
Love this!! 5 stars (dunno why one won't light up) Easy to use and holds small valuables/money. It would have to be smashed with something very heavy to break into - I don't think it could be easily broken into, so it is definitely sturdy, strong and safe. Easily fits into my night table drawer. Small enough to pack into a suitcase for travel. Highly recommend! ... show more
Reviewed in the United States on February 21, 2026 by NanaBev
    • Perfect Little Safe for Peace of Mind!
Color: Gunmetal Grey Size: 9.8 x 5.5 x 2.6 inches
The Master Lock Portable Small Lock Box has been an incredibly useful addition to our household. It’s compact, sturdy, and perfect for securing important items like cash, IDs, keys, and small documents. I really appreciate the “set your own combination” feature - super easy to personalize and even easier to use. Its portable size makes it great for travel, dorm rooms, or just keeping valuables tucked away at home. It’s lightweight but still feels durable and reliable. I love knowing that important items are protected without needing a big, bulky safe. The safe is easy to open and I find it very useful when traveling. Overall, this little lock box offers great security, convenience, and peace of mind. Highly recommend for students, travelers, or anyone who wants a simple and effective personal safe! ... show more
Reviewed in the United States on December 5, 2025 by Deb Thornton
    • Good little safe
Color: Gunmetal Grey Size: 9.8 x 5.5 x 2.6 inches
It worked well on vacation. I holds your valuables and it seems sturdy. I’m sure if it’s stolen, it could certainly be broken into. If you check bags, I recommend putting it in there and not on a carry on. It was the first time in over a decade that my bag was set aside for inspection because of how this safe looks in their x-ray scanner. ... show more
Reviewed in the United States on March 10, 2026 by moi

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