This is a pack of 15 Stainless Steel clutch bearing spacer shims. This kit contains five 0.1mm, five 0.2mm and five 0.3mm thick Stainless Steel shims. These shims are perfect for shimming 1/8th scale clutch bells to get the correct amount of play. Correctly shimming your clutch bell bearings to have a small amount of play is important to help maintain the life of the clutch bearings.