The Van Mark Guide Bearing replaces any worn-out bearings on the TrimCutter, TrimFormer, or Quick Score. This bearing is sold in a quantity of 1. To replace all of the bearings on your TrimCutter, TrimFormer, or Quick Score, you must order a quantity of 4. The guide bearings will also reduce wear and tear on the blade by keeping it cool. Replacing your guide bearings on Van Mark products helps keep if functional and extends its lifespan.