I have one of the HTG Easy Cool's 6" and it sucks balls a total piece of junk.
1)If you open it to a normal level to change bulb the case deforms and cracks edge of glass.
2)The "air seal" is pointless when it leaks air from every weld plus the foam gasket isnt even cut to the correct size so not a real seal.
3)The socket blocks more then 50% of the air and creates a whistling sound.

I got pissed smashed it and got 2 Sun System Yield Master II hoods from Igrowhydro.com for 89 bucks a piece wow day and night difference in quality and craftsmanship.Plus a lot cheaper in price.

Yield Master 6" AC Reflector - GROW LIGHTS - LI-RFYM-R6

Smokey