This lamp is Mega-Ray's top-of-the-range 100 watt SB Par-38 Narrow Flood Lamp which has been shown in tests to produce similar amounts of UVB to natural sunlight! - along with adequate heat to create a basking spot at the recommended distances, in many circumstances.

Mega-Ray SB 100-watt narrow-flood is a 100-watt SB Par-38 True Frosted Flood Lamp. A true flood lamp, it will disperse usable UVB in a 30" circumference at a 20" distance. The MINIMUM distance setting of 12" will produce approximately 150-200 microwatts per square centimeter (uW/cm2) of UVB and 900-1200uW/cm2 of UVA. The MAXIMUM distance setting of 20" will produce 50-75 microwatts per square centimeter (uW/cm2) of UVB. (Distance is measured from lamp face to basking spot or reptile for optimum UVB and heat.).

Most people with UVB meters are getting 18+ months use out of these SB bulbs.