Technical data:
1) Weight: 16.5g
2) Power: AG5(1.5V X 3) Battery
4) Alarm Angle: 15 - 30 (Adjustable)
5) Rating for the Voice Pressure:1 cm away from the voice hole >85DB
6) Certificate of EMC Compliance (CE MARK): G3M20202-1106-E-16 (March 13,2002)
It's wearing on the ear of a driver and works on the principle of electronic balance.
