Features: * It can be used anywhere and without distance limit. * Up to 200 phone numbers are allowed. The 1st to 3rd user numbers can receive SMS, and the 4th to 6th user numbers can receive calls in case of alarm. 1~200 authorized phone numbers can call T201 to turn on/off Relay0. * External monitoring of AC/DC power status, AC/DC power on/off will send SMS and call 6 preset mobile phones immediately. * 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 temperature, power alarm or normal, it can be linked 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 password for identification, unknown callers will be ignored. * It can be programmed via SMS commands with password protection. * GSM web-based, suitable for many applications. (Temperature, power status, solar panels, DC voltage). Tips: 1. Please read the user manual carefully before installing and configuring the control unit. 2. Install the system in a hidden location. 3. Avoid pouring water into the control unit. 4. Ensure the connection to the main power supply is secure. Specifications: Product Name: Monitoring Relay Rated Voltage: DC 9V ~ 24V / 1A Working Temperature: -10 ℃ ~ + 60 ℃ Storage Temperature: -20 ℃ ~ + 60 ℃ Relative Humidity: 10-90%, non-condensing Working Frequency: GSM: 850/900/1800 / 1900MHz 3G WCDMA: UMTS 900/2100 MHz 3G CDMA2000: UMTS 850 / 1900MHz 3G: UMTS 850 / 2100MHz Communication Protocol: GSM PHASE 2/2 + (including data service) Output relay relative voltage: 3A / 240V AC SIM card: Nano type, 3V Antenna: 50Ω SMA Wired switch: support Temperature sensor: Temperature: -55℃ ~ +125℃: 0.1℃ Alarm output: output voltage = DC input voltage, current: <1A Backup battery: 3.7V / 1000mAH (with battery or without battery optional) Material: ABS Item size: approx. 8.8 * 7.3 * 6 cm / 3.5 * 2.9 * 2.4 in Package Information: Package Size: Approx. 12.5 * 9.3 * 7 cm / 4.9 * 3.7 * 2.8 cm Package Weight: Approx. 215g / 7.6 oz Note: Please allow 0-1 cm error due to manual measurement. Please 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 * Temperature Sensor 1 * User Manual (QR Code)