The Bogen SLC is a continuously variable volume control that can remotely control the volume of up to 150 self-amplified speakers. The SLC fits into a single gang electrical box. The controller is a continuously variable passive volume control that can remotely control the volume of up to 150 self-amplified speakers. The unit's output terminals are able to control up to 150 speaker inputs. Output wiring is made via two separate two-position screw terminal blocks for input and output signals. The SLC?has a rugged and attractive stainless steel plate with engraved lettering. The SLC measures 2-7/8" W x 4-5/8" H x 2" D and weighs 2 oz. Remotely control the volume of up to 150 self-amplified speakers Rugged and attractive stainless steel plate with engraved lettering Mounts in a single gang electrical box Easy and secure terminal strip connections Passive (requires no DC?power)