Designed to be a drop in replacement for pre-CBS Fender basses equipped with Kluson reverse wind tuning machines, the BT3 Xtender gives the ability to drop up to a major 2nd on your low E string. Specifically machined for these basses, these also work on a range of reissue models and custom builds. Key Features: Effortless Drop Tuning: Drop a Major 2nd (E-D) and if your strings have standard thickness cores, you can go as low as a 4th (E-B) DoubleStop Functionality (optional): DoubleStop feature gives you a tuning position between the high and low for a total of three tunings on your 4th string Precision Engineering: Precision Laser cut and machined construction with no casting or stamping 27:1 tuning ratio: Provides ultra-precise tuning adjustments, ensuring you stay perfectly in tune across all tunings. Easy Installation: Fits 11/16" [17.5mm] headstock holes Smooth Action: Adjustable tension nylon bearing system Built to Last: Stainless steel key prevents tarnishing and rust where you touch the tuner the most Mounting hardware included. Replay Guitars is a proud authorised Hipshot retailer.