uxcell 2mm to 2mm Bore Rigid Coupling Set Screw L26XD10 Aluminum Alloy,Shaft Coupler Connector for 3D Printers, Motor Accessories: Amazon.com: Industrial & Scientific
Amazon.com: Sydien 2Pcs 5mm to 10mm Motor Shaft Coupling Aluminum Alloy Flexible Stepper Motor Coupler Motor Connector Joint for 3D Printer, CNC Machine : Industrial & Scientific
SDTC Tech 1/4 inch Flange Shaft Coupling Metal Axis Bearing Fittings Rigid Coupler for Stepper Motor RC Model (2 Pack): Amazon.com: Industrial & Scientific
NEMA 17 Shaft Adapter – The Smell of Molten Projects in the Morning
Shaft Sleeve 1/4Inch(6.35mm) Shaft Motor to 11mm Bore Adapter for RV030 Worm Gear Speed Reduce: Amazon.com: Industrial & Scientific
9.5 3/8" x 10mm Flexible Shaft Coupling Stepper Motor Coupler D25 L30: Amazon.com: Industrial & Scientific
Pololu Aluminum Scooter Wheel Adapter for 5mm Shaft | POLOLU-2673 | Core Electronics Australia
Shaft Adapters - Design Engineering
Imported Stepper Motor Flexible Shaft Coupling Coupler 6.35x8mm : Amazon.in: Car & Motorbike