Features: Dual systems and circuits design. The lock will alarm and change to standby circuit, when the main circuit is with low power. When the standby circuit is with low power, it lock will alarm. Dual motors design. You can start the standby motor to open the lock, when the main motor is broken down.   Indoor touch Design, you can open/close the lock by touch the lock body when indoor. It is very convenient. Tiger lock method, more safe and stable. No keyholes outside, there is no way for thieves. Automatically lock function. If you don’t need this function, you can close it by yourself. Add type-C external power source function. Make sure the lock works when battery was dead. (battery not included) Easy installation on all kind of doors, very convenient.   Specifications: Host Machine: Color: Black Material: Zinc Alloy +ABS Size: 165*87*36mm Frequency: 433MHz(±500KHz) Power Supply: 4 AA Batteries (Not included ) /AC Batteries Life: About 12 months Unlock Methods: Remote Controllers Operation Range: Within 20m (no obstacles) Transmission Method: RF Optional Function: Tuya app wifi optional   Remote Key: Color: Black Size: 60*30*10mm Weight: 25g Function Unlock/Lock, Standby changed Key Power Supply: CR2032(3V),battery not included Battery Life: About 6 months Standard Number: 2pcs (included) Max. remote controls Number: 10pcs(not included)