Climax Metal Products - Shaft Collar: One Piece Split Shaft, 2-3/4″ OD, Stainless Steel - 75236679 - MSC Industrial Supply
Amazon.com: Metal Shaft Collar, 6MM Shaft Limit Ring Stop Collar Set Positioner Locator 2Pcs for High Speed Working for Industry : Industrial & Scientific
Pack of 4) Shaft Collar Bore 6mm, Aluminum Alloy One Piece Shaft Collar Clamp Style, 20mm OD, 8mm Thickness, with M4 Set Screws: Amazon.com: Industrial & Scientific