Built for use with magnetic low voltage transformers, the Lutron DVLV-600P Diva Series dimmer is to be used on single-pole systems only. Additionally, this dimmer is for 450W lighting (600VA). This VA (volt-ampere) rating includes the magnetic transformer heat losses and the lamp load. The watt rating, in this case 450W, is the maximum lamp wattage based on assumed 20 percent transformer loss. This dimmer will fit on standard wallplate openings and is available in seven unique colors.