For a "professional" service these guys do NOT have professional knowledge. Had a lens with backfocusing issue and had explain over and over what that means. As i wanting to use the lens on different nikon bodys that didn't all have af fine tune i return it. I wanted to try another copy of the same lens as it may have been better.(my other lenses don't have this issue.) but i was told the lens didn't have a fault and they would refund it! I never said there was a fault just a backfocus issue but no matter how many emails and phone calls no one seemed to understand :( Took them over a week to handle is matter. Also the protective packaging could've been much better.