Anchor 12" Square Anodized Aluminum Hatch. NEW trim ring gasket included. This hatch is made from 1/4" thick marine grade aluminum and has a stainless steel locking mechanism. It features a water tight seal and anti-slip surface. The hatch mounts flush on the deck. It has a clear opening of 10"x10", a deck cutout of 12.5"x12.5", and the OD of the deck flange is 15.5"x15.5". Recommended fastener is #12- 316 stainless steel tapping screws (3/4" to 1" long -depending on deck thickness)