Bomar Commercial Grade Aluminum Inspection Hatch 7-15/16 inch Round Single-Dog Low Profile. Hatch is made of Almag-35 Aluminum and has removable lid for easy access. Locks down with a single t-handle. Non-skid surface. Hatch Opening: 7-15/16 inches (185 millimeters), Outside Deck Flange: 10-7/16 inches (248 millimeters), Cutout: 8-1/2 inches (216 millimeters), Extends below deck: 1/2 inch (13 millimeters), Weight: 3 pounds.