

🔐 Unlock smarter, not harder — your keys, your rules.
The Master Lock 5440EC is a rugged, Bluetooth-enabled outdoor lock box designed for realtors, property managers, and landlords. It securely stores up to 5 keys or key cards, offers app-based access management without Wi-Fi, and provides tamper alerts and usage logs. Weather resistant to -40°, it’s ideal for vacation rentals, remote properties, and business use, with scalable app integration for personal or enterprise control.























| Brand | Master Lock |
| Item dimensions L x W x H | 1.13 x 3.25 x 4.8 inches |
| Lock Type | Electronic |
| Material | Metal |
| Recommended Uses For Product | Vacation rental properties, unmanned remote locations, real estate, and business applications with multiple locks and users Recommended Uses For Product Vacation rental properties, unmanned remote locations, real estate, and business applications with multiple locks and users See more |
| Special Feature | Portable |
O**E
Great experience
Great product, very sturdy and safe, the app takes a bit of time to understand, but my wife is smarter than me, so no problem! Super convenient not to have to key codes, works really well. Thank you.
E**E
Good Box that Seems to Work Well
I bought this key safe box for my 91 yo father who has lost his house keys twice in the last 2 months. I figured that putting a key in the box outside his door was the best way to ensure that he'd never lock himself out. From the moment I received the box, I was impressed with it. It is heavy and has Bluetooth connectivity that allows it to be programmed from the Master Lock app. Plus you can download access logs to see exactly who and when used it. It can allow for several (I think up to 5 or 7) different access codes that can be personalized and assigned to different people allowing each person their own code and the ability to use their own phone to unlock the box via Bluetooth. It has lots of customization options and works better than I expected. The lighted keypad is a easy to see; the buttons are big and sound a tone and blink when you push them; and the ability to create long or short PINs is a plus. It feels sturdy and I think it would keep whatever you put inside it safe. I do have a couple constructive comments though... First, to open it, you have to grab it from both sides and pull on the flared edges of the door which folds down to open it. Though not a big deal, this would seem kind hard for someone with grip issues. I assume it's built like this so you can't easily take a pry bar to the key safe, which I understand, but it also makes it a little harder to use for people with disabilities or the elderly... Or if it got wet, it might just be a little hard to open for a regular person if it got slippery. Maybe if the door popped open slightly when disarmed, that would be helpful and make opening the door a little easier. Lastly, I have more of an installation tip than a criticism... maybe a criticism of the directions. When you install the Master Lock app and assign phone privileges to the app, make sure that you set the privileges for the app to access your phone's Bluetooth all of the time, not just when the app is running. I know this sounds strange, but I had all sorts of connectivity issues with the app communicating with the box when the app only had privileges when the app was on. The app would recognize the box but it wouldn't update it consistently with the new passcodes. It would download the access log, but I sometimes had a problem unlocking the box using the app. The app would see the key safe, but didn't seem to stay connected to it. The BT connectivity was very shoddy until I changed the apps privileges. Once I did that, the app recognized the box consistently and worked as designed. Unfortunately, I don't remember seeing anything in the directions about this tidbit, and there's no troubleshooting section in the included fold out directions to help you. The directions are poor and basic at best and barely helped you through the install process. Maybe if I had known how to set the app's permissions from the directions, my comments would be different, but unfortunately, that tidbit of info isn't there and so it tainted my experience until I figured it out. It was so bad I even considered returning the key safe as defective. Luckily I installed the app on my Android phone and noticed the "allow use all the time" privilege that I didn't see as a choice so I didn't select it the first time I installed the app on my Dad's Android phone. (My Dad has a Motorola phone, and I have a Samsung). Once I went into the app's privileges and fixed it, all the issues I had went away. Needless to say, it's working now and I think it'll provide the security that my Dad needs.
S**Y
Simple to Install, Looks Extremely sturdy
This seems to be a very secure box. It is hard to grab onto to try to leverage off the wall. I found the app quite intuitive. I only have two suggestions. The product should come with instructions on which app to install. There is an enterprise app, and a home app. The former fills up the screen and you have to scroll to discover the second one. I recommend using longer screws. After penetrating the siding or stucco of your house, there is about an inch left to penetrate studs. I substituted 2 inch screws.
H**L
Do Not Buy This Piece Of Junk
I bought the Digital Master Lock Lock Box because I thought it would make our lives easier renting rooms in our home. It completely did the opposite. 1. Keys locked in and can't get out: For two months we haven't been able to get our keys out of the lock box. It completely defeated the purpose of getting it in the first place. A waste of our time and my money. We can't get our keys out (due to the master key holder isn't home very often and it was their phone that was programmed - see below) and now I can't return it because the return date has long passed. Our keys are still locked in the box. Our code isn't working. The codes that my partner programmed aren't working. The box isn't opening. We can't get it off the door. It's basically cost us hundreds of dollars if we can't get our keys out. 2. The description makes it look easy to program the lock box and give a code to guests or whomever you want to let enter your house. The catch, you have to be there and you have to be the master owner registered with the lock box. Major problem for us. My partner is gone nearly all of the time. She set up the lock box on her phone. Guess who is home most of the time and running things in the house? I can't program the lock box. Logged in using her ID and password and since my IP address or whatever all information is missing and I'm locked out of key areas within the app blocking me from being able to control check-ins. My girlfriend called Master Lock once, but they needed her to do something and timing wasn't working out. I've been on her for two months to get this resolved, but she's rarely home. I'm so angry and frustrated I can't express it here without getting kicked off of Amazon. My partner is trying to get the keys out again this weekend when she's home. I don't know what is going to happen. Absolutely worthless. Waste of money. DO NOT BUY. Master Lock or Amazon, if you are reading this I want my money and my keys back!
C**S
Sturdy but a bit glitchy
This is a heavy duty product that I think will stand up to the elements. However the actual unlock is a bit glitchy. It does not open up when I am near it as described, but rather I have to open the app to make it unlock. Perhaps there is a setting on my phone causing this problem? I have been searching online but haven’t figured it out. Either way I am happy with the product and think it seems to be of good quality.
I**V
Great product at this price point!
I was impressed with the lock after the setup was complete. There were challenges with paring it up to the phone, the booklet and lock case point you to an outdated app that is no longer used and was replaced with an app titled Master Lock Vault Home. You will be prompted with that message after you have downloaded the app and started filling it out. The app itself seems to be pretty intuitive and I could figure out many functions it offers such as: unshackle the lock, see the lockbox access history, remotely unlock, create/delete different code combinations right from the app. Aside from the directions on the packaging pointing to downloading the wrong app, it was great and in fact, I am thinking of buying another one. Additionally: Whoever designed this product and the way it integrates with the app really put in a real good effort with functionality, you can even set the time zone! Great job! One other thing that comes to mind using this app is its security. I believe some sort of security check needs to occur when opening this app on a phone since it controls other locks. There are numerous examples out there that use some sort of a sec. check i.e. FaceID or passcode. Looking forward to more of this awesome functionalities 👍
S**T
Extremely reliable in spotty wireless and internet areas
I love the unit. Use it for my VRBO rental in Tahoe that has limited Wireless access and internet can be spotty. The unit is extremely reliable. I’ve been using it for 8 months now and no guest has ever had an issue...that is success in my book. But there are quirks that originally were not what I expected. This quirks could be unacceptable based on your situation: . I do not ask guests to download the APP. It isn’t very good, people don’t want to install APPs on their phone for one time use and remember a username/password, and I’m not sure how reliable it is in areas that have poor wireless access - I tested the APP for opening the box and it didn’t always work (it is likely due to my home not having good wireless service near the box). This means that Instead of using their phone to open the box anytime during their stay, I give the guest temporary codes to open the box to get and return keys. . The temporary codes are basically valid for 8 hour increments. Some people may not like that, but for my home, this unit was the best option. And I find the 8 hour range wasn’t as limiting as I thought. For checkin and checkout, I just give them different temporary codes based on their arrival/departure time range. Again, I’ve been doing this for 8 months now and it works for me. In reality, reliability trumps all in my book!
J**N
Sturdy Electronic Lock - Less Features than needed
I bought a few of these Bluetooth electronic keyholders to try out. Out of all of the ones I bought, I would say this is the most sturdy one and had the most thoughtful design for example, changing the battery would probably be the easiest to do on this unit compared to the other ones that I bought. It was very easy to connect the app to this and set a code. The one reason I didn’t go with this option is because of the price in comparison to the other ones I bought and the features of the app. I was not able to set a temporary passcode for my own defined time range. I was only given set ranges of time to choose for temporary password. For example I could have chosen 9 AM to 10 AM but I really needed 9 AM to 12 PM.
Trustpilot
1 month ago
2 months ago