Keep your reptile happy and healthy with the Aqua Culture Compact Fluorescent Bulb for Reptiles. This 13-watt bulb provides essential UVB rays for pet reptiles while maintaining lower levels of safe UVA. This fluorescent bult has an excellent UVB to UVA ratio and provides beneficial UVB up to 6"-11" from the lamp to the basking site of the reptile. The lamp should be placed outside your reptile's enclosure. For optimal health, provide your reptile with a 12- to 14-hour light cycle. Using a 12- to 14-hour light cycle, your bulb will produce sufficient UVB rays for 12 months. Make sure your reptile is happy and healthy with the Aqua Culture Compact Fluorescent Bulb for Reptiles.