R-Zilla - Desert Flo Bulb 21 Watt 36 T5Delivers UVB light levels essential for desert reptile health.Full-spectrum illumination accents subtle pet colors.Styles to fit fluorescent, incandescent light fixtures.Bring a ray of desert sunshine to arid reptile habitats.When it comes to the bone health of a desert reptile, the extra daily dose of UVB light provided by a Desert 50 bulb (50 microwatts per second/cm2) is as essential as proper food and water for long term strength. The Desert 50 family of bulbs also provide needed UVA light, plus visible-spectrum illumination that makes skin coloration more vivid and viewable. Get all this in a family of high-efficiency bulbs designed to fit most major fluorescent fixture types (compact, T5 and T8). Incandescent lamp users also have the option of a Coil Bulb that screws into a standard light socket. Desert 50 bulbs are designed for 3500 hours or twelve full months of average.36 in21 Watt36.62 in L x 2.00 in W x 1.00 in H - UPC: 96316670891