Wifi/automated lockboxes for key storage

[Tim McCahill]

Hi all - 

I own three properties in three different neighborhoods and am weighing the pros and cons of keeping keys for all three at one of the properties. In my mind, the ideal system would be a wifi-enabled lockbox or key box my contractors could access when they needed to do work, and which would allow me to change the access code after they return the keys. Does such a thing exist? Does anyone have experience with wifi or automated locking systems at their properties? 

Many thanks!