I bought this Encore Smart Lock for my apartment building for security purposes, to always keep the exterior doors locked for security, to allow tenants to unlock and lock the doors from their apartment and to allow delivery companies to unlock the door, place packages inside the building and lock it back up. These locks have worked seamlessly and have bought more for other properties and my own home. I have referred these locks to multiple people. This smart lock is also great for short term rentals, you can create a unique code for each traveler and delete it after their stay has expired.