Description The Brooks BMP173 Tension Bolt 64mm can be used on the following Brooks saddles: B17 in all of its steel versions B17 Short Professional S B66 & B67 B66 S & B67 S B68 & B68 S B72 & B73 Finesse Flyer S in all its versions & Countess Swift CHROME (not Titanium) Swallow CHROME (not Titanium)