R-Zilla daylight full-spectrum T5 bulb provide visible light output in the 6,700K nanometer range. This helps bring out subtle colors in a reptile"s skin that makes everyday viewing more dramatic. Daylight lamps emit a high-intensity light output that simulates natural sunlight which generates the photosynthetic energy to stimulate lush plant growth, making this ideal for terrariums with live plants. Daylight bulb is designed for 3,500 hours or 12 full months of average use. Bulb operates at 21-watts. Measures 2-inch length by 36-5/8-inch width by 1-inch height.