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..

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,..

Features4G 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 limit..

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..