Earth Worth 1000 Watt Hydro Hippo Grow Light Kit Dual Bulb System for Hydroponic - Get Started Easily 2-in-1 Ultra-Cool Tube Reflector works wuth HPS or MH Bulbs Combined 6" Air Cooled Reflector Hood with Ultra-Cool Tubebest cooling. Large reflector hood enables more efficient lighting than standard reflectors. Superior air cooling does not compare to other general reflector hoods. 6" air vent works perfectly with an optional 6" exhaust fan system (NOT included)