Amazon.com: Letool 4pcs U type groove pulley nylon Guide Pulley Rolling Bearing U Groove Roller Wheel 8x40x20mm for Driving Mechanical Equipment, or Used in Doors and Windows : Industrial & Scientific
U Groove Wheels And Rollers
LBER 2 Inch Roller Wheel Bearings U Groove Pulley Wheels Detachable Heavy Duty Grooved Wheel for Material Handling and Moving|Lifting Tools & Accessories| - AliExpress