Features: *No lock hole design, it completely abandons the traditional key and lock, open and close by remote control or APP, realized real security. *It supports touch design, it can be locked and unlocked by touching the lock body when indoors. *Add USB external power source function. Make sure the lock works when battery was dead. (batterynot included) *Four unlock modes optional: Phone APP unlock, Remote control unlock, indoor Button unlock, indoor Touch unlock. *Tiger lock method, more stable and safe. Easy installation on all kind of doors, very convenient.