Stainless Steel
Inner Diameter 42mm x Outer Diameter 52mm Shim
Thickness 0.1mm, 0.2mm, 0.3mm, 0.5mm x 1pc./each
It corresponds to Crankshaft Radial Ball Bearing 52mm.
An axial shim set which supports radial ball bearing (52mm) of crankshaft used on vehicles like MONKEY/APE. 

* Details
You can adjust clearance caused by individual differences of crankshaft and crankcase. This clearance caused by individual difference will generate movement towards crankshaft axis, though it may be small. As a result, it causes loss of power during the process of power transfer from crankshaft to transmission, and eventually degrades engine power. Also, the repeated axis movement of the crankshaft will reduce uncomfortable sound, vibration, and damage to the crankcase itself.
Especially, when this part is installed on vehicles with big bore engines, the engine can fully demonstrate its power and can suppress vibration.