Features:1. No lock hole design, it completely abandons the traditional key and lock, open and close by remote control(RC without Battery).2. It can be locked and unlocked inside by touching the lock body.3. USB external power source function, Make sure that the lock works when the battery is empty. (Battery not included)4. Four optional unlocking modes: Unlocking phone APP, unlocking remote control, unlocking indoor button, unlocking indoor touching.5. More stable and secure. Easy installation on all types of doors, very convenient.Specification:Lock:Power Supply: 2x AA batteries(not included)Transmission Frequency: 433MHz(500KHz)Operation Range: Within 20mUnlocking Mode: APP unlocking&Remote control unlocking& indoor button/touching unlockingSize: 15.5x8x3.5cmRemote Controller:Battery(Each): 1x 3V batteryStandard Number: 4 (included)Max Controller Number: 16 (not included)Function: Lock &unlockingSize(Each): 6x3x1cmPackage Includes:1x Lock1x Lock Body Bracket1x lock4x remote key1x USB power cable1x BT adapter1 bag x screwsincludes:1x Lock1x Lock Body Bracket1x lock4x remote key1x USB power cable1x BT adapter1 bag x screws