This IceCap 660 electronic ballast can run 2 to 4 lamps totaling 16 feet of fluorescent bulbs. Icecap ballasts can run HO (800 MA) , VHO (1500 MA) and standard (425 MA) fluorescent bulbs including T5, T8 & T12s, with bulb lengths 2' to 8' totaling up to 464 watts. This allows for various bulb configurations. Soft start and high frequency operation prolongs lamp life and increases light output of non-VHO lamps. These IceCap ballasts can also be used with PC bulbs. They are lightweight - just 2lbs, cool and silent.