Standard MRP Roller Casing. Replacement casing only (PU material) for Standard MRP Roller used on all System chain devices including LRP.Sold EACH.(MRP part # is 20-1-029-B.)Â Note: Casing Excludes bearings and bolt hardware. You can reinstall your existing hardware and bearings into the new casing.Note: Fully assembled option with NEW bearings and bolt also available;Ison part# CHMRURK (MRP part # 20-1-030-B)