1. Safe: The access control wireless door opener uses caller ID for identification and ignore unknown callers. A maximum of 200 authorized phone numbers can be configured at a specified time. 2. Wireless Remote Control: Quad-band: 850/900/1800/1900MHz, can be used in the global GSM network. There is no need to provide remote controls or buttons for different users. 3. Features: The door opener relay can add or delete users via SMS text commands; the relay closing or opening time is programmable; it can be operated anywhere without distance limitation. 4. Free Call: Relay operation return SMS confirmation to owner or authorized phone, this function can be by user. No call charges. The GSM GPRS trunk switches rejects calls from authorized numbers and then performs an open/close operation on the first "ring". 5. Application: One output with relay rating 3A/240VAC for connecting switches of a door or machine. Multiple applications. Suitable for doors, bollards, barriers, garage doors, shutters and access doors or machines) Description: GSM Door Opener RTU5024 is a powerful GSM relay that can be used for authorized access control, control doors, switching of remote devices and parking systems. Also, it can be used where it is necessary to remotely turn on/off a system, machine or device by making a free call from a mobile phone. Specification: Model Number:Gate Opener Relay Switches GSM Frequency:Quad-band 850/900/1800/1900MHz Network:4G Raw output:NC/NO dry contact, 3A/240VAC DC power supply:9-24VDC/2A Power consumption:12V input maximum 50mA / average 25mA SIM card:support 3V SIM card Antenna:50 SMA antenna interface Temperature range:-20-60 Humidity range:90% relative humidity Color:As Shown Material:plastic Package Contents: 1 * door opener set 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 picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.