Its just a set up to get the action/neck right. Ive put on brand new strings.He said the intonation is off, which is weird as I set that myself. (open string 12th fret/harmonics etc) Its convenient because he's literally 100 yards down the road from me. He said it will take a week and a half..Im thinking its expensive, but for convenience, petrol etc.. Im expecting a very well playing Sei Jazz bass.