... , 180°adjustable angle sensor.* Power supply by batteries AA or external power.* Minimal power, and high power conversion rate, more than 90 ... : DC4.5V* Audio frequency format: WAV* Audio rating output power: 0.5W (=8Ω d=1%* Frequency response: 2020KHz* ... Speeding alarm , vehicle speeding alarm , overspeed alarm , alarm ,anti-theft alarm ,security alarm ,security system, bell, chime, door chime, ...