UltraGrow Cool Tubes are available with 6-inch or 8-inch diameter ducts which provide the ideal solution for minimizing heat build-up problems in a grow room. A minimum of 300 CFM of fan power is recommended per Cool Tube unit when housing a 1000W HID bulb. Compatible with 400W, 600W or 1000W metal halide or high pressure sodium lamps. Each cool tube comes with an internal reflector, and also has exterior reflector wings to enlarge the growing area. Reflector includes heavy duty brackets, pre-installed mogul socket with 15 foot long lamp to ballast cord. Tempered glass is capable of holding heat temperatures of 5000 btu's.