Master Lock Lock Box, Bluetooth® Wall Mount Key Safe, 3-1/4 in. Wide, 5441DLOCK BOX APPLICATION: For indoor or outdoor use; wall mount lock box is best used for key and access card storage; large internal cavity allows secure storage for multiple keys; weather resistant to -40°EASE OF USE: Use your smartphone to unlock Bluetooth lock box or enter numerical code on lock keypad for easy backup entry when your smartphone isn't present; built for permanent installation on a flat surface, installation hardware includedSHARED ACCESS: Share temporary or permanent access via Bluetooth or keypad code with invited guests; Monitor activity, and receive tamper and low-battery alerts with the free Master Lock Vault eLocks app for Android and iOSVALUE: No monthly data package or shared access fees; no activation or monthly usage fees; No long-term contractsSPECIFICATIONS: 3-1/4 in. wide lock body; Internal dimensions - 3-39/64 in. height, 2-1/2 in. width, 1-7/64 in. depth; replaceable CR123A battery (included)