The Lutron DVSCLV-603P Diva Satin dimmer is designed specifically for lighting systems using 3-way wiring and magnetic low voltage transformers. Additionally, this dimmer is in the Diva Satin series of Lutron dimmers meaning it has the modern look of Diva Series dimmers and the wide variety of colors in the Satin palette. Only use this dimmer if your lighting system has 120V, 600VA 450W lamps. The VA (Volt-Ampere) rating includes the magnetic transformer heat losses and the lamp load. The watt rating is the maximum lamp wattage based on assumed 20 percent transformer loss.