Every reptile owner should have this item! It should be a legal requirement that you either (a) own one of these gauges or (b) pay to have your headlights checked every 6 months if you want to own a reptile whose life literally depends on proper lighting. I use 3 MVBs for my reptile that provide different UV and heat gradients (it has a 10x10 room for habitat and half a real tree to climb, I also use 5 more lights to simulate sunrise and sunset and ceramic heaters). Mfg recommendations and suggested lamp choices are usually close, but not always. UV output may last SIGNIFICANTLY LESS and/or longer than manufacturer predicted. Without one of these gauges, you would never know and could (albeit unintentionally) harm your reptile. You'll also save overtime by getting the most out of your UV lamps. *Sounds like a publicity stunt. It is not. I don't work for SolarMeter and paid $250. The simple fact is that the importance of lighting for reptiles really cannot be overstated. And please don't take your lighting recommendations from the pet store. Please investigate. If you take care of your reptile, you will buy one of these.