Ruland JD32/51-98R is a zero-backlash jaw coupling spider designed to fit Ruland hubs that have an OD of 2.000" (50.8mm). It is a component in a three-piece design consisting of two aluminum hubs and an elastomeric insert called the spider creating a lightweight low inertia coupling capable of speeds up to 8,000 RPM. This three-piece design allows for a highly customizable coupling that easily combines clamp or set screw hubs with inch, metric, keyed, and keyless bores. JD32/51-98R is made from polyurethane and has 98 Shore A hardness allowing for the highest torque capacity with limited compliance. Ruland jaw couplings have a balanced design for reduced vibration at high speeds.Hardware is metric.