I took them to rc injection. Dropped them off the called the next day saying one was bad, I ordered another off eBay and dropped it off along with my side feed injectors they called next day saying all 12 were cleaned tested and good to go. Got the paper work with them and everything of test results. The Merc dealer my buddy works at uses this place for fuel injectors but never took direct injectors there. I asked them two different times if they do direct injectors and they said ya no problem.