Signstek Aluminum Flexible Z Axes Coupler 5mm x 8mm 5/16" RepRap 3D Printer Prusa Mendel Silver
New Precision Aluminum Flexible Shaft Coupler 5MM X 8MM. Perfect fit from 5mm steeper motor shaft to ballscrew, shaft or threaded rod 5/16" or 8mm. Screws hold very tight. Dimensions 25mm x 18mm