This lamp is Mega-Ray’s 275 watt SB Par-38 Narrow Flood Lamp which produces more UVB and UVA than a standard Mega-Ray® 100 & 160 watt lamp, along with more heat, and can therefore be used at greater recommended distances. Mega-Ray® SB 275-watt narrow-flood is a 275-watt Self Ballasted Par-38 True Frosted Flood Lamp. A true flood lamp, it will disperse usable UVB in a 30″ circumference at a 34″ distance. MINIMUM distance setting of 34″ will produce approximately 150-200 microwatts per square centimeter (uW/cm2) of UVB and 900-1200uW/cm2 of UVA. MAXIMUM distance setting of 46″ will produce approximately 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.)