MroMax Nylon Plastic Pulley U-Shape Groove Wheel 4x18x6mm Guide Bearing Pulley Rail Ball Wheel for Driving Mechanical Equipment, Doors and Windows White 4Pcs: Amazon.com: Industrial & Scientific
4PCS x Shower Door Rollers,Roller Diameter 19/23/25/27mm, for The Bathroom Pan Glass Sliding Door Pulleys/Runners/Wheels,Strong Load-Bearing Capacity, Ultra-Quiet,CY103-4PCS
MroMax Roller Idler Bearing Pulley-6 x 30 x 9mm Sliding Conveyor Nylon Wheel with 626Z Bearing for Furniture, Hardware Accessories and Mobile Door White 2Pcs: Amazon.com: Industrial & Scientific