The Particle Alarm & Hanger is a set that features a water-resistant alarm that runs on a single 12V23A battery and a free hanger. The alarm features low power drain, adjustable volume and tone and a night light function. It has detachable snag ears and a memory function that keeps your settings intact.Adjustable volumeAdjustable toneNight light function Low power drainDetachable snag earsMemory functionWater-resistantSupplied with a free hangerRequires 1 x 12V23A battery