Salco Products (AHC20TAS) 20-Inch Aluminum Tri-Wheel Airslide Hatch Cover features three (3) 1-Inch hand wheel slots on a 24-Inch bolt circle, which are 120 degrees apart. Length from the center of the hatch cover to the center of the hinge bolt hole is 12-1/2-Inches. Includes a white FDA Neoprene gasket.