M...
Review confirmed by purchase 
The shim fulfills its role – it's 2 mm thick, enough to perfectly set the angle of engagement between the piston teeth and the rack. It's light enough (1g) that it doesn't affect the piston assembly speed. The only downside is the material quality – the protruding collar, meant to stabilize the shim in the roller's hole, broke off during a test assembly. I had to use a drop of glue to hold it in place.
