1、Built-in 3G module, compatible with GSM version. With remote switch function, free call through authorized phone, can be operated from any place, there is no distance limit, and up to 1000 authorized phone numbers can be configured within a specified time. 2、High security, use caller ID for identification, unknown callers will be ignored. Built‑in rechargeable battery for power failure alarm. 3、You can add or delete users through SMS text commands. There is no need to provide remote controls or keys for different users. A wide range of applications, including doors, bollards, fences, garage doors, shutters, and doors or machines. 4、The relay switch will return the SMS confirmation to the owner in the number or authorize the call. This function can be edited by the user. The switching time of the relay is programmable. 5、There are no phone charges. After receiving a call from an authorized number, the GSM trunk switch will turn on/off the first "ring". Item Type: Gate Opener Material: ABS PlasticModel: RTU5024 Digital Output: NC/no dry contact, 3A/240VAC DC Power Supply: 9-15VDC/2A Power Consumption: 12V input maximum 50mA / Average 25mA SIM Card: Standard SIM card Antenna: 50Ω SMA antenna interface Temperature Range: -20- 60°C Humidity Range: 90% RH Battery Capacity: 1000mAh (Built-in) Size: Approx.  3.23x2.99x1.06in / 82x76x27mm 1 x 3G/GSM Gate Opener 1 x Antenna 1 x USB Data Cable 1 x USB Programming Cable 1 x User Manual