From Callaham:
This upgrade eliminates the years of problems and frustration of a Bigsby Vibrato restringing. This again is a polished stainless steel shaft that is counterbored for the string ball ends. Thread the string through the hole and up to the tuner. Works for all models and comes with retaining clip.
Fits the following Bigsby models: B3, B5, B6, B7, B11, B12 and finally B16.