Brand: SureMotion Item: Drive coupling hub Material: Aluminum alloy Requires: DC-JS55 series spiders Outside Diameter: 55mm Bore Diameter: 3/4in Attachment Style: Clamp Overall Length: 75.4mm Coupling Type: Jaw type Maximum Angular Misalignment: 0.9 degrees Coupling Size: 55 Maximum RPM: 8480 Maximum Parallel Misalignment: 0.23mm SureMotion drive coupling hub, jaw type, aluminum alloy, clamp, size 55, 3/4in bore. Requires DC-JS55 series spiders.