1. Adopt GSM communication, without any distance limitation, it can be used anywhere.

2. 850/900/1800/1900MHz quad-band GSM frequency, can work in global GSM network.

3. Without call charges, the GSM GPRS relay switch rejects calls from authorized numbers and then performs an open / close operation on the first ring.

4. Wide working voltage, support DC 9 - 24V power supply, and with anti-reverse protection design.

5. Using SMS to set parameters remotely, easy to operate and easy to use.

6. Support 200 groups of numbers, each group of numbers can be set to control the relay within a specified period of time.

7. One relay output, the authorized number will be closed after the incoming call, and it will be automatically opened after the set time.

8. Add or delete users with SMS text commands, simple operation, convenient for using.

9. After the authorized phone controls the relay, it can send action text messages to the user.

10. Between 0-999 seconds, the relay closing time can be controlled arbitrarily, where 0 means: the relay will open 0.5 seconds after closing, and 999 means: the relay will remain closed until the permission number is dialed in.

11. You can query the current status of the device (relay status and GSM signal value) through SMS instructions.

12. You can upload the current status of the device to the first user by SMS in a timely manner.

13. Use the clock on the module and send yourself a text message to synchronize after each boot.

14. Metal case with IP30 protection. The metal housing is safely isolated from the system, which is especially suitable for industrial control field applications.

15. Compact size, (L x W x H) 90 x 70 x 27mm/3.5