Product Name: GSM Receiver 2g/3G/4G GSM Gate Opener Access Relay Switch Remote Control by Free Call Home Alarm System Security for Automatic Door Opener Channel: 2CH Certification: CE, FCC, RoHS, Intertek Usage: Personal, Auto, Door, Window Type: Wireless Product Name: GSM Receiver 2g 3G 4G Working Voltage: 3A/240VAC Trademark: RKING Transport Package: Box Origin: China Product Description GSM receiver 2G/3G/4G GSM Gate Opener Access Relay switch Remote Control by Free Call Home Alarm System Security for Automatic Door Opener1.Advantages> Quad-band, can work in the worldwide GSM Networks;> No call charges. theGSM GPRS Relay Switchrejects the call from authorized number then carries out the turn ON/OFF action on the first 'ring';> Multiple applications. (gates, bollards, barriers, garage doors, shutters and access doors or machines);> Secure - Using caller-ID for identification, unknown callers are ignored;> Can be operated from anywhere, no distance limit;> Add or remove users by SMS Text command;> No need to provide a remote control or keys for different users;> Up to 200 authorized phone numbers can be configured at the specified time;> One output with relay rating 3A/240VAC for connecting the switch of the door or machines;> The relay action will return a SMS confirmation to the owner or authorized call in number, this function is editable by user;> The relay close or open time is programmable;> Multiple applications. (gates, bollards, barriers, garage doors, shutters and access doors or machines);Setting:> SMS command;> Operate from anywhere anytime, no distance limitation;2. Applications:> Remote open/close swing/sliding gates, doors, shutters, garage doors,locks with a free call!> Residential: Door,gate,garage access control, electronic fan,microwave,air-conditioner control.> Industry:Remote switch equipment, for example: street lights, solar power, motor, inverter, PLC, pumps, fans, etc.> Agriculture:Remote control pumps, etc.> Business:Remote control electronic boxes,bright billboards,LED signs,etc.Packing List:Gate opener unit *1Antenna*1Note:2G,3G or 4G network, please contact me which one you need.