... used out, can connect external battery case to supply power2.4 Alarm for low power: When battery power is low, ... system,Locking system We manufacture high quality RF card hotel door lock,RF card locker lock,Digital locker lock,Energy savingswitch,Doorbell switch,Touch ... ,producing,assemble and testing,all did by ourselves.4) SCC’s strict quality control management & competitive price, we gain orders ...