it will be a 600w ballast pushed to the limit to help exceed the normal lumen output of a 600w hps bulb, it will push its lumen output right over the edge without burning the bulb out with the same amount of electric kw cost at your electric meter, for example if you put the 600w bulb in to a 1000w ballast i can guarantee you it will burn the bulb out, you will probably even smell it burning, and if you put a 1000w bulb in to a 600w normal ballast you will get 600w. its a bit like buying a small banger of a car and putting nitrous oxide in to it, and then booting the guts out of it until the engine blows up. so if your hps bulb lasts for say 3 months of growing in a normal ballast, you may be only able to get 2 months of high power lumens with this turbo boosting baby.