Helix Polyurethane Chain Roller Maintenance-free, polyurethane chain roller uses a nylon sleeve instead of roller bearings - saving half the weight. Features: Lightweight polyurethane chain rollers are designed with no bearings Wheels run on a nylon sleeve for maintenance-free performance Half the weight of roller bearings Available in two sizes: Small: 20.5 mm W x 31.5 mm diameter Large: 20.5 mm W x 38 mm diameter Made in USA Sold each Universal hardware included Kit included 1 roller (image shows 2 rollers for reference only)