High UVB output. Effective up to 30cm (12) Provides necessary UVB rays for optimal calcium metabolism. Stimulates appetite, activity and reproductive behavior through uva radiation Usually turn on light for 4 hours per day to remain its lifetime; long time light treatment is not good for your animals. NOTE:Dont use it with adjustable switch/dimmer bulb holder, because the bulb has a rectifier in it. Specifications: UVB Output: 5.0/10.0 (optional) Wattage: 13W/26W (optional) Base: ES-E27 (standard screw fitting) Voltage: 110V How to choose ? UVB5.0 is Suitable for reptiles living in tropical forests or tropical areas:Such as: IG green iguanas and other iguanas, Burmese tortoises, star tortoises, radiation tortoises, red legs and other most continental tortoises. UVB10.0 is suitable for reptiles living in tropical deserts, such as king lizards, leopard tortoises, sukada tortoises, radiant tortoises, yada, angaloka, lion lizards, and succulents.