Enpoint&trade; CNC Motor Encoder Curved Jaw Coupling 8x10mm 20x30mm Jaw Clamp Style Shaft Coupler with Aluminum Jaw Coupling Hubs and PU Elastomer Spider for Servo Motors Coupling hubs made from high grade aluminum bar stock for precise fit, superior strength and bright finish Balanced hub design to support higher RPM with reduced vibration Polyurethane material of the spider dampens impulse loads while minimizing shock to the motor and other sensitive equipment Easy installation and maintenance, anti oil and corrosion resistant; customized size available upon request Considered fail safe because if the spider becomes compromised the jaws of the two hubs interlock for direct power transmission allowing the machine to be shut down safely