The Allparts Tremol-No is a patented device that is added to an electric guitar equipped with a tremolo/vibrato unit. If you break a string or drop tune the low E to D, the other strings will stay in tune. It allows guitarists 3 playing options: - tremolo on - in this position your tremolo functions as normal. You can raise or lower the pitch of notes with the tremolo. -tremolo off - in this position, you'll enjoy the benefits of a hardtail bridge, where the tremolo doesn't move at all; no lowering or raising of a note's pitch via the tremolo, and the other strings remain in tune should you break one of them. -tremolo dive only mode - in this position, you can only lower the pitch of notes. Tremol-No comes in 3 versions: 1-PIN-TYPE is designed to work with tremolo blocks that do not have a flat base, such as those that are rounded or beveled (to allow for more tremolo travel). 1.5mm SPRING HOLE DIAMETER IS REQUIRED TO USE THE PIN-TYPE SEE AMAZON Listing for PIN TYPE fit. 2-LARGE CLAMP type (SOLD ON THIS PAGE) is designed to work with tremolo blocks that are thicker than 10mm.The Large Clamp is designed to attach to very thick tremolo blocks (up to 14mm), like those found on vintage Strats, PRS, and upgraded Floyd Rose tremolo blocks. 3-SMALL CLAMP type is designed to work with tremolo blocks up to approx. 9mm in thickness.This includes almost all Floyd Rose and FR-licensed tremolos. It works on fulcrum-based Kahler tremolo systems too.