I've just fitted these saddles to my 'Partscaster' and the results are really good.I fitted a Bigsby Vibrato arm, with a string bar which allows the strings to move about, and traditional saddles which have only two shallow grooves from which the strings can slide out too easily.This set of saddles has much deeper grooves so I could choose the correct one to line up the strings correctly, and be sure they were not going to slide sideways.The action screws are easy to set and adjust.I didn't used the supplied intonation screws and springs because of the way I had configured my ashtray, but they look very good quality.Overall, this was a really worthwhile upgrade for my Tele, and sorted out my string issues.Excellent.