Not sure what you're saying here. Air cooled reflectors come in all sizes, you don't have to build one. Here is an inexpensive large reflector that is air-cooled:Na hes got a 600 aswell, but without a cooltube, hes got a wider reflector, although his temps are very high. I need to try and make a big reflector really but im shit at makiing things like that, anyone got any advice on making a bigger reflector for cooltubes and how to fit em?