These undercabinet lights use Xelogen bulbs, which contain 99% Xenon gas. They use less energy, are rated for over 10,000 hours, have a low operating temperature, are resistent to shock and vibration and emit a cleaner, warmer light that appears more like daylight than flourescent. They have a low, sleek profile, and are not visible under most cabinetry. They are easy to open, have a high-low-off switch, and are available in 5 sizes and 3 finishes. 2" H, 4 1/2" L, 16" W| Aluminum Material | (2)18W T5 Wedge, Bulb Supplied | White Lustre Finish| Item Weight: 1.90 LBS |