1. 2.4GHz patented smart embedded wireless technology

2. One receive can work with two transmitters simultaneously

3. Transmitters have PIR sensor to detect human move to trigger alarm on transmitter

4. Receiver has high-power alarm sound output

5. Receiver can listen to sound from any transmitter

6. 8KHz ,16-bit digital audio

7. 300 meters open-field communication distance

8. Use AAA*3 or Li-ion battery

9. Adjustable volume

10. Low-battery indication

11.LED volume indication