I have 2 of these Sun System Blockbuster 6 Inch Air Cooled Reflectors in my grow room with 600 watt bulbs and they work great. The glass only gets warm and the tops are cool to the touch.
Sun System Blockbuster 6 Inch Air Cooled Reflectors Put Out
They are great for keeping the heat down. Sturdy and well made and easy to open too. This is a top performing light hood with an intense square footprint that gives great penetration.