Climax Metals MC-16 Black Oxide Plated Steel Set Screw Collar, Metric, 16mm Bore Size, 28mm Outside Diameter, M6 x 6mm Set Screw: Tools Products: Amazon.com: Industrial & Scientific
100 Piece Silver Tone Metal 28mm Outside Diameter Split Key Rings - Walmart.com
Amazon.com: uxcell Nitrile Rubber O-Rings, 34mm OD 28mm ID 3mm Width, Metric Sealing Gasket, Pack of 10 : Industrial & Scientific
MAEDLER deep groove ball bearing single row inner diameter 15mm outer diameter 28mm width 7mm shielded on both sides SKU: 61902-ZZ-MAE - Maedler North America