This Valve-exhaust is the most expensive of the items that make up this Valve assembly.
Parts such as the Valve: Shim,t=2.90, Collet,retainer, Valve-exhaust, Shim,t=2.75 are included in the Z750p5 1987 United Kingdom / Mph Valve parts fiche.
In this schematic the "Collet,retainer" is used most often.