Off-Road Chain Roller, Lightweight Polyurethane Roller W/Nylon Inner Sleeve, Small, 32MM, Yellow. These Lightweight Polyurethane Off-Road Chain Rollers Are Designed With No Bearings And Run On A Maintenance Free Nylon Bushing. Most Dirt Bikes And Atv'S Require Two Per Machine. They're A Great Way To Save A Lot Of Weight On Your Machine, And Much Less Expensive Than Titanium Nuts And Bolts. Available In Two Sizes: Small, 32MM, & Large, 39MM. Seven Colors Available.