Preco’s Short Range Sound (SRS) back-up alarm keeps excessive noise pollution to a minimum. The SRS alarm helps maintain a safe warning signal for those in the danger zone of backing vehicles without, while minimizing annoyance among neighbors and pedestrians, Preco says. It works by emitting sound at multiple frequencies but only within a narrow range. Several other alarms use a wider range of frequencies that result in a sound more indistinguishable from ambient noise, according to Preco.
