The original and genuine Bigsby vibrato unit. Originally manufactured in the mid 1940's and is still being made in the U.S.A. today. The B3 model is mainly used for guitars with a long string travel length from bridge to tailpiece - such as a Gretsch 6120. It comes complete with an arm, 4 mounting screws to attach the unit to the side of the guitar and a spring to support the vibrato mechanism.  Fitting instructions are included although we recommend a local guitar Luthier to fit it for you if you are unsure about carrying the work out yourself.