OptioTM OPT20HP and OPT15HP Dimmer Modules contain two high-performance IGBT dimmers. IGBT Dimming technology provides quiet lamps, quiet dimming modules without buzzing, long lamp life, higher energy efficiency, less waste heat, and short circuit immunity. Each dimmer employs solid-state Insulated Gate Bipolar Transistor (IGBT) devices which are rated at no less than triple the dimmer's rated capacity. They are c.U.L. recognized and rated for operation at 120VAC, with a capacity of 2000 watts per dimmer (OPT15HP module is rated for 1800 watts per dimmer). The module is ruggedly designed, fully enclosed module. Modules are easily installed into an OptioTM Lighting Control Panel, and may be easily interchanged with other OptioTM modules.