Master Lock 4400D Indoor Bluetooth Smart Padlock

Regular Price: $70.00

Special Price $38.19

Availability: In Stock - Usually Ships within 24 hrs

Master Lock 4400D Indoor Bluetooth Smart Padlock
2-inch Wide Body
7/8-inch Shackle Clearance
9/32-inch Shackle Diameter

Product Description

Your Smartphone is the Key!

Master Lock Bluetooth® Smart Padlocks turn your smart device into a key! With an advanced, easy-to-use app, you don't have to worry about losing keys, forgetting combinations, or unauthorized key duplication. True keyless convenience provides greater control and flexibility as you share access with friends, family, colleagues and employees. Enjoy peace of mind as you monitor the lock's activity and recieve tamper alerts and low battery notifications. With anti-shim technology offering maximum security, these padlocks combine ergonomic features with strength, durability and reliability, making them the perfect choice for use at home, office, job site or school.

A Smarter Padlock!

Share Access
Schedule guest access days, nights or 24/7; share temporary access via manual code.

Monitor Activity
View lock history, including registration, guest addition/deletion, unlock/open/relock activity, tamper and low battery alerts.

Tamper Alerts
Multiple unsuccessful keypad entry attempts trigger email and app notifications.

Low Battery Alerts
Padlock LED, email and app notifications.


Key Features:

  • Your smartphone is the key to your padlock - no more lost keys or forgotten combos!
  • With free app, enjoy speed & ease of use, share access, have greater control with temporary digital keys/codes
  • Receive tamper alerts & low battery notifications
  • Replaceable CR2450 battery can be jumped with an external battery if the battery dies in the locked position
  • Backup access using an up/down/left/right directional code on the lock keypad
  • Easily add/remove guests & schedule guest access to 24/7 or limit to days or nights
  • Locker Mode allows for maintaining a locked state while the phone is stored inside of a locker
  • Lock history log tracks important lock events
  • Hardened boron alloy shackle for superior cut resistance
  • 2" (51mm) wide metal lock body
  • Shackle diameter .281" (7mm); shackle clearance: 7/8" (22mm) high, 13/16" (20mm) wide
  • Designed for indoor applications
  • Warranty Info:  Limited One (1) Year Warranty. Visit for complete warranty details.


4400D Specs


How long will the 4400 series battery last?
The 4400 series battery should last at least 2 years in Touch Unlock Mode and 4 months in Swipe Unlock Mode with regular use.
What if my phone is lost or stolen?

Reset Keys allows the lock Owner to revoke all Bluetooth access to the lock, including their own. The Owner and all guests will receive updated Bluetooth credentials on their mobile devices.

LOST / STOLEN DEVICE NOTE! The owner of a lost or stolen mobile device should first go to the web site and change their username and passcode.

To Reset Keys, the lock Owner should:

  1. Select the lock from the Locks list.
  2. Touch MANAGE LOCK in the upper right corner. Enter your passcode, if prompted.
  3. Touch the SETTINGS icon Settings Icon in the upper right corner.
  4. Touch RESET KEYS.
  5. Follow any additional instructions in the app to save the changes to your lock. This step must be completed for each lock the lost or stolen device had access to.
What if my lock battery dies?
If the lock battery dies while the lock is closed, it can be unlocked using an external battery.

When the battery has less than 20% of estimated life remaining:

  1. The center LED on the lock keypad will light yellow.
  2. An email notification will be sent to the lock owner.
  3. A Low Battery icon will appear in the app.
  4. A Low Battery warning will appear in the lock's history.

To replace the battery on the 4400 series:

  1. The center LED on the lock keypad will light yellow to indicate low battery.
  2. Unlock and open the lock.
  3. Pull out the battery drawer at the bottom of the lock and remove the old battery*.
  4. Install a new CR2450 battery with the positive (+) side facing the back of the lock.
  5. Close the battery drawer.
    * The battery drawer will only fully extend when the lock is in the open position.
Replace Battery On 4400 Series


Register and Add Your Lock Replace Your Battery - Indoor Model 4400D Bluetooth Smart Padlocks Get Started Bluetooth Smart Padlocks - Informational


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Ratings & Reviews

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Most Helpful Customer Reviews
  • 1 of 1 people found the following review helpful

    More pros than cons


    I can only find 1 issue, which it is crucial for this device. This issue is it's battery "tray".

    The place where the battery is stored can easily come off. With enough force, a mischievous person can easily pull it and render the device useless because it'll easily break.

    I am sure the lock itself can be hacked... But that's something I am not too concerned about.

    All in all, if this issue was fixed, it'll get my 5 stars. Maybe add a locking system for the battery. I am tempted to glue it with a heat gun and see if that'll work. A knife can easily remove the glue, but I'd feel safer if people had to use tools instead of mere force.

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  • 1 of 1 people found the following review helpful

    Doesn't work like I hoped

    I love this lock but it's just about useless to me with the bluetooth feature. I have to re-pair it everyday if I want to use my phone to unlock it. I've uninstalled/reinstalled and still have to pair it first.
    I still love it for the digital combo tho. I have a coworker who picks our locks. He can't break into this one. He figured he'd fix me by breaking mine so that I can't get into it. I noticed the battery compartment has dents in it from someone trying to get in it but the security feature of not being able to take out the battery unless opened, took care of that. Next he "accidently" dumped liquid soap all over it. He said it kept flashing lights. When he left I tried the combination and it opened fine. I cleaned off the soap on the outside and now have it sealed with tape so it can't happen again. It's been weeks since the soap "accident" and is still working fine.
    I guess I should knock off a star or two due to the bluetooth issues but truth is, knowing how sturdy it is and how easy it is to use the digital code, I'd buy it again even if it wasn't bluetooth.

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  • 1 of 1 people found the following review helpful

    Is good, but you need patience

    This lock is great, as long as you have patience. More times than not, you just go into the app, then press the button on your lock to unlock it.

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  • 1 of 2 people found the following review helpful

    The Future of Padlocks

    Just ordered this about a week ago and was surprised how fast it actually came. Was on the phone with Phil and he is extremely knowledgeable and easy to talk to. The price seemed a little high for a lock, but I use it all the time. Once I got it I quickly realized why its priced where it is. I go to the gym frequently and am an idiot and forget my combo all the time or mix up the numbers so it got frustrating. With this I just unlock it from my phone, which I always have on me or if my girlfriend wants to borrow it I share it with her and all she had to do was download the app.

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  • 1 of 2 people found the following review helpful

    Story Behind the One Star Value

    I am the type of person that never writes reviews on anything...... EVER. But I have a story I had to share. I am the type of girl that likes new things or things that I think are tech savvy and was looking for a cool gift for my boyfriend.... at the time. Anyway I ran across this site and saw this product and decided to give them a call. I ended up speaking to some guy named Hunter who gave me some details and I decided to buy it for my boyfriend. Long story short I gave him the gift he added me to the lock and basically ended the relationship by locking me out. The lock itself is super cool and savvy and definitely worth the price. I gave it one star in value because I can't use that lock anymore because he locked me out and it reminds me of that idiot. I decided I should share this story and definitely will be buying one soon.

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