The new ReptiSun-« Compact Fluorescent lamps use a special UVB transmitting quartz glass for maximum UVB penetration. Cool burningcompact fluorescent bulbs screw into standard threaded sockets, eliminating the need for a separate ballast. Lamp can be oriented eithervertically or horizontally in your reptile hood or clamp lamp fixture. UVB emissions help prevent or reverse metabolic bone disease andUVA increases feeding, mating, and other natural behaviors. 5% UVB Output, 30% UVA Output, FULL SPECTRUM.