To learn more about HID lighting read our buyer's guide HID Lighting Buyer's Guide. Also check out our HPS Bulb Comparison Test pitting nine different HPS bulbs against each other.
Air cooled reflectors help keep your grow room cool by having an intake and exhaust port on each end for easy airflow access. These reflectors come with ports from 4" to 10" in diameter. Larger reflectors tend to have a larger footprints, but smaller reflectors can help you fit in tight grow rooms with low ceilings.