Are you often called upon to play low D or B notes but dont want to switch to a 5 string? Youre in good company. Thats why the BT2 has been a not so secret weapon of elite bass players since 1982. The ability to instantly drop the tuning of your low string and then back again with the flip of a lever is a great way to keep the gigs coming! The BT2 is a direct replacement for the Schaller BMF tuner that was first found on CBS era Fender basses manufactured between 1967 and 1982. Since then, the BMF tuner has been featured on countless boutique builds and Custom Shop models. Drop a Major 2nd (E-D) and if your strings have standard thickness cores, you can go as low as a 4th (E-B) Robust stamped and machined steel construction 27:1 tuning ratio Fits 11/16" (17.5mm) headstock holes Adjustable tension nylon bearing system Stainless steel key prevents tarnishing and rust where you touch the tuner the most Clover key style Mounting hardware included