Hex Drive Size: 9/16"; Width From Flat to Flat: 0.551 inch to 0.564 inch; Overall Height: 0.438 inch to 0.468 inch;
High Quality Material: Made of Stainless Steel 304 (18-8) which provides good strength and corrosion resistance in bad environments without the need for time consuming and costly maintenance.
Will NOT COME LOOSE: With a nylon insert inside, the lock nuts greatly reduce loosening under vibrations and torque.