AP21-BH2 EXTRA LOUD BREAK BUZZER SYSTEMPLUG and PLAY - NO WIRING REQUIRED . . .Single Schedule, Single Zone with up to 30 signals per day. The system consists of an AP21LV Time Switch mounted in a keylocked box (7"W x 12"H x 4"D),pre-wired to 2 Four-Inch, Extra Loud Buzzers and a 120 VAC to 24 VAC power module. A 90 footcable is included for each buzzer so the Horn/Buzzers can be located up to 90 feet from the keylocked box in each direction.Mounting hardware is included. Simply hang the enclosure and Horn/Buzzer, plug it in, and enteryour program. This Buzzer must be mounted at least 10 feet above employee work areas