Features:GSM network communication, no distance limitation, can be used anywhere.Works with a Nano SIM card, users could dial the SIM card number to open the door.No phone charges, no distance limits,..

Overview:THE WH-300 4G GSM controller is designed to remotely control a relay output on an authorised incoming call. The unit will check the database of allowed users, reject the call and only sw..

Overview:THE WH-300 4G GSM controller is designed to remotely control a relay output on an authorised incoming call. The unit will check the database of allowed users, reject the call and only sw..