These items are CNC cut and are produced from sheets of 4mm Okoume marine grade plywood.
The oval pairs are identical-one attaches UNDER the deck - the second attached to the top of the hatch cover.
If you are following KayakCraft, it quickly becomes obvious that these are shaped very differently from those in the manual. These came about as a means of creating larger openings with easier access to getting gear into and out of the kayak.
Builders can choose to install either ONE or TWO hatches on their kayak. This item for sale refers ONLY to the larger AFT HATCH. Look for the BOW hatch rings on the shopping list.
The small inside flanges are there to allow for the installation of the swell nut lock down levers employed to seat the hatch cover against a gasket to keep the water on the outside of the craft.
If you elect to use a different system to secure your hatches, the small flanges can be cut off or simply left in place.
The swell nut (expanding rubber sleeve does the swelling) levers are a simple way to secure the kayak hatches when under way.
THREE are required for the bow hatch and four are required for the aft hatch. These items are priced individually and are included here as options.
A supplementary instruction manual and a full sized template for the hatch opening is included.
1) Aft and bow hatch rings
2) Installed with swell nut lock down levers
3) Single lock lever