LOCK BOX APPLICATION: for indoor and outdoor use, wall mount key safe is best used for Key and access card storage, large internal cavity allows secure storage for multiple keys. EASE OF USE: Use your smartphone to unlock wireless lock box or enter numerical code on lock keypad for easy backup without smartphone. For security reasons, the lock box does not unlock if the synchronized phone is not within Bluetooth range SHARED ACCESS: Share temporary or permanent access via Bluetooth or keypad code with invited guests, monitor activity, and receive tamper and low-battery alerts, schedule access now or in the future by choosing from suggested time range SPECIFICATIONS: 83mm wide lock body, 12, 7cm H x 83mm W x 59mm D, replaceable CR123A battery (included). Includes mounting hardware for easy installation, weather resistant to -40° MASTER LOCK VAULT HOME APP: free app for Android and iOS to manage key safe access