- Valcom paging horn - 15 Watt - One way - Easy Omni-Lock I-Beam clamp mounting system - Weather resistant - Indoor/outdoor - Built-in amplifier - Built-in volume control - Stainless steel hardware - 360* rotation - Shatter-proof base fits seven standard electrical gang boxes - White - Dimensions: 7.38inchH x 10.0inchW x 10.4inchD - VALCOM POWER UNITS (-18)