wafu 018u smart door lock invisible wireless remote controller bluetooth app unlock for indoor

no lock hole design, it completely abandons the traditional key and lock, open and close by remote control or phone app, realized real security. tiger lock method, more safe and stable. no keyholes outside, there is no way for thieves.add usb external power source function. make sure the lock works when battery was dead. (battery not included) three unlock modes easy installation on all kind of doors, very convenient..syi