UVB prevents metabolic bone disease, and this National Geographic Solarheat Mercury Vapor Bulb (160 Watts) provides both UVB and UVA for radiation, visual light and heat. Heat is essential for your reptileAAATMs activity and digestion. Only at PetSmart. Features: Provides the benefits of natural sunlight Includes: 1 Solarheat Mercury Vapor Bulb (160 Watts) Intended For: Reptiles Wattage: 160 W Color: White Dimensions: 5.3 in L x 5.3 in W x 6.5 in H Compatible With: Reptile Terrarium Heat Lamp Cautions, Warnings, or Side Effects: DO NOT mount at an angle; mounting at an angle will reduce burn life. DO NOT place a light fixture inside the reptile habitat; it can cause life threatening burns to your pet. DO NOT allow product to come in contact with carpet, draperies, or other flammable material. DO NOT use in wet conditions. DO NOT repair or modify. DO NOT use in damaged condition. DO NOT exceed electrical ratings. Keep away from children. For use above screen-top enclosures ONLY. WARNING: Bulb will get hot when in use.