Feature: 1. The GSM SMS environmental alarm is specially used to remotely monitor the temperature, humidity and power status of the site through the wireless GSM network. 2. When the temperature, humidity, and power status exceed the high or low threshold, it will immediately send SMS reminders or call 6 preset mobile phones. 3. When temperature, humidity, power alarm is normal, it can be connected to the Realy1 output operation. It is very useful when the temperature exceeds the specified value and the air conditioner needs to be turned on immediately or the dryer needs to be turned on due to water overflow. 4. Relay0 with dial‑up or SMS remote control. Up to 200 phone number can authorize the number. Since the call is not answered, the dial‑in control in GSM is free. 5. It only checks the caller's number, and if the number is authorized, it responds via relay activation. This can be used for parking latch control, GSM door openers, remote control machines, etc. 6. Up to 200 authorized phone numbers. User numbers 1‑3 can receive text messages, and user numbers 4‑6 can answer calls when an alarm occurs. 1‑200 authorized phones can dial to turn on/off Relay0. 7. Based on the GSM network, it is suitable for many applications. Such as temperature, humidity, power status, solar panels, DC voltage. 8. It is suitable for vegetable greenhouses, household temperature and humidity detection and power monitoring, while monitoring temperature and humidity and external power off/on situation. Specification: Item Type: GSM Temperature Alarm Relay Material: ABS Use: Suitable for vegetable greenhouses, household temperature and humidity detection and power monitoring 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 Communication Protocol: GSM PHASE 2/2 + (Including Data Service) Relevant Voltage of Output Relay: 3A / 240V AC SIM Card: Nano 3V Antenna: 50ΩSMA Wired Switch: Support Temperature and Humidity Sensor: Temperature: -40-80°C, Accuracy: 0.5°C Humidity: 0-99RH%, Accuracy: 3%RH Siren Output: Output Voltage = DC Input Voltage, Current: <1A. Package List: 1 x GSM Temperature Alarm Relay1 x Temperature and Humidity Probe6 x Connection Terminal1 x Antenna1 x Manual