Erlandson Technology Scooter ETI Kevlar Drive Belt 669-18-30K All belts are certified to be within .020 of OEM required manufacturing specs. Most replacement belts can have up to 1/2in. variance in length. Longer belts affect the operation of the clutches and create inconsistencies in shifting. This also can cause excessive wear on the clutches. Top Cog construction that strengthens side wall