or remove users by SMS mand. The relay or open time is programmable. Can be operated from anywhere, no distance limit. -band, can work in the worldwide GSM Networks. No need to a remote control or for different users. - Using caller-ID for identification, unknown callers are ignored. 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. Multiple applications. (gates, bollards, barriers, garage doors, shutters and access doors or machines). The relay action will return a SMS confirmation to the or authorized call in number, this function is editable by . No call charges. the GSM GPRS Relay Switch rejects the call from authorized number then carries out the turn ON/OFF action on the first 'ring'. GSM Frequency: -Band 850/900/1800/1900MHz Gigital Output: NC/NO dry contact, 3A/240VAC DC Power Supply: 9-24VDC/2A Power Consumption: 12V Input Max.50mA/Average 25mA : Support 3V Antenna: 50 ohm SMA Antenna Interface Material: ABS Color as shown Package Contents: 1 x GSM Door Opener 1 x antenna Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.