Bill has tested many reflector materials and angles to insure that the lamp fixtures are emitting as much of the UV as possible. We have even had reflector material manufactured directly into the tubes themselves. (This did not have the ideal result). We have now settled on the current shape and size of the reflectors for each of our lamp products. Not only the shape and size but also to make sure that tubes have ideal cooling as well. The reflector is as important as the tubes in most cases. You can have a very expensive lamp fixture but without proper placement of reflection you will not reap the rewards.