Features: * It can be operated anywhere, and no distance limit. * Up to 200 authorized phone numbers. The 1st ~3rd user numbers can receive SMS, and the 4th ~6th user numbers can receive calls when alarm occurs. 1~200 authorized phone numbers can call T201 to turn on/off the Relay0. * External AC/DC power status monitoring, AC/DC power on/off will send SMS and immediately call 6 preset mobile phones. * Timer report can be set every few hours, and its status/value will be automatically sent to 6 preset mobile phones immediately. * Support remote reading of historical data via SMS. * Automation system, when the temperature, power supply alarm or normal, it can link to Realy1 for operation. * Alarm output, when alarm occurs, it will output for 30 seconds. * Internal rechargeable battery can be used continuously for 6 hours. * Safe, use caller ID and password for identification, unknown callers will be ignored. * It can be programmed via SMS commands with password protection. * Based on GSM web, suitable for many applications. (Temperature, power status, solar panels, DC voltage). ? Tips: 1. Please read the user manual carefully before installing and setting up the control unit. 2. Install the system in a hidden place. 3. Avoid pouring water into the control unit. 4. Ensure that the connection to the main power supply is secure. ? Specifications: Product name: Monitoring Relay? Rated voltage: DC 9V~24V / 1A Working temperature: -10 celsius ~+60 celsius Storage temperature: -20 celsius ~+60 celsius Relative humidity: 10-90percent , no condensation Working frequency: GSM: 850/900/1800/1900MHz 3G WCDMA: 900/2100 MHz UMTS 3G CDMA2000: 850/1900MHz UMTS 3G: 850/2100MHz UMTS Communication protocol: GSM PHASE 2/2 + (including data service) Relative voltage of output relay: 3A / 240V AC SIM card: Nano type, 3V Antenna: 50 Ohm SMA Wired switch: support Temperature sensor: Temperature: -55 celsius ~+125 celsius :0.1 celsius Alarm output: output voltage = DC input voltage, current: less than 1A Backup battery: 3.7V / 1000mAH (with Battery or without Battery optional) Material: ABS Item Size: Approx. 8.8 * 7.3 * 6cm / 3.5 * 2.9 * 2.4in Package Information: Package Size: Approx. 12.5 * 9.3 * 7cm / 4.9 * 3.7 * 2.8cm Package Weight: Approx. 215g / 7.6oz Note: Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! ? Package List: 1 * GSM Temperature Alarm Relay 1 * Temp Sensor 1 * User Manual(QR code)