I purchased 20 1000W ballasts from Welthink in Virgina Beach, VA. Within 6 weeks ALL 20 failed, one almost burned down my house. These units are serious S**T!!! To top it all off when I called Sonny (ironic name) at Welthink he told me that the smoked units were not covered under the 3 year swap out warranty they claim. He tried to feed me some bulls**t that the damage wasn't covered and that I had tampered with the units. Having not even seen the faulty units, I find it hard to believe that plugging them in is considered "tampering" with them. Save your money and buy a ballast from Lumatek or another reliable source. These Welthink made in China crap ballasts aren't worth their weight in horse s**t.