Dual systems and circuits design. The lock alarm and change to standby circuit, when the main circuit is with low power. When the standby circuit is with low power, it lock alarm. Dual motors design. You can the standby motor to open the lock, when the main motor is broken down. No lock hole design, it completely abandons the traditional key and lock, in the fully opened and closed by remote controllers, realized the real security. Indoor touch Design, you can open/close the lock by touch the lock body when indoor. It is very convenient. 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. (The product printed words depending on the batch, but this does not affect use) Color:Black Material:ABS Package Contents: 1 * door lock 2 * remote controls Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.