ENTR™ Kits Specifications:BLE Smart (Bluetooth Low Energy)2.4GHz communication frequency between the ENTR unit and accessoriesRechargeable Lithium-ion batteryBattery power: 7.4V 2600mAHCharging input: 12VDC @ 1AOperating temperature: -10°C ~ +50°CENTR unit dimensions: 150 x 55 x 54mmWeight: 380gProtection rating: IP44Mobile app support: Minimum iPhone 4s; iOS 7 and up. Minimum Nexus4, Samsung S3, Galaxy Note; Android 4.3 and up Features:No more keysUnlock your door using your smartphone, remote control, touchpad reader and fingerprint reader (accessories sold separately)Self-locking door for peace of mindEasy to install simply replace existing cylinder with ENTRIdeal for any door type or sizeSecure, encrypted wireless communication between system elementsBattery operated systemHigh Security PATENTED Euro Profile Cylinder with Dimple Keys ENTR™ Cylinders