Master Lock has released a shackle version of its well-known Bluetooth-enabled Key Lock Box.

Known as the slightly tongue-twistery Portable Bluetooth Select Access Smart Key Lock Box, it's the same relatively compact box but now has a shackle on the top which means it's portable providing you have something to lock it to. 

As with other Master Lock Bluetooth kit it's controlled via the Vault smartphone app, available for iOS and Android. As long as you have your phone on you, and Bluetooth is turned on, you can press the button on the front of the safe to open it. You don't need to get your phone out your pocket and hold it near the box.

Master Lock Connected Key Safe [Bluetooth or Combination [Shackle] [Outdoor] -5440EURD-Select Access Smart Lock Box, One Size

Amazon

The owner or admin of the safe can give permission for any of their contacts to be able to open it via Bluetooth, and can set whether access is permanent, or just on a temporary basis. Access can even be set by day and time, so you could give limited access to a builder for example, just for when you know they're going to be at your house when you're out. 15 guest codes can be shared at any one time. 

If the app isn't installed, access can still be granted by entering a numerical code on the backlit keypad on the front of the safe. 

Not only can the app be used to grant access to other users, but it can also warn of any suspicious activity, such as someone trying to break in.

The built-in battery claims to last for two years, but when it does eventually run out, and someone still needs access before replacing the CR123A battery, a jump feature gives you a small boost of battery so you can still access the keys.

Also check out the prices for the original wall mounted lock box here: 

Master Lock - Select Access SMARTΓäó Bluetooth Key Box - Large

Amazon