I recently purchased this item as a new edition to my grow room. Unfortunately i was soon to find that it was not up to par. I always test my ballasts with a wattage meter to ensure they are running at the correct wattage. Even though this ballast is advertised and sold as a 600 watt ballast, to my disappointment, it only runs at 500 Watts! This is well below what it is advertised at and meant my bulb was only getting 450 Watts of power! I tried to get a refund from the shop i purchased from, but was told that it wasn't faulty! He said it was common knowledge that they don't run at 600 watt. Well i certainly wasn't told! Anyway, had no choice but to keep it, so i stuck it in a little veg tent. 2 weeks later, the ballast melted from electrical failure. Good job i had it on a house brick! All in all not happy with this product, especially as it is extremely dangerous. Avoid like the plague!