The Lutron 2W-T825-120-1 is a Tu-Wire 25 watt, 36 in. long dimming ballast. This model is designed for retrofit applications. This energy saving dimming ballast works with Lutron two-wire fluorescent controls; it contains one lamp per ballast. The Lutron 2W-T825-120-1 provides high performance dimming without changing the existing switching wiring scheme.