Bomar Hatch Hi-Pro 18-7/16 X 18-7/16 BOM-N208010A

Style A-external hinge. Anodized heavy-duty aluminum frames. 1-1/2" height above deck. Extra high sealing lip on base. Heavy-duty acrylic top and heavy-duty hinges. No sharp corners to snag lines or sails. Quick acting, adjustable tie down dogs. Locked vent position.
O.D. of deck flange" 20-1/4 x 20-1/4
Hole Cut Out" 18-1/2 x 18-1/2