Single Input/Source, Wall Amplifier in a UL Rated Double Gangbox. The AMP1SGB delivers 40 watts of power and can effectively drive up to four OWI surface mount speaker or ceiling mount speakers. One line can drive up to 10 self-amplified speakers. Lower noise feature and protection from shorts and overheating. 15 Volt DC Level 5 power supply included. Available in one, two or four speaker combination models either in black or white.