Stainless Steel 316 Marine Grade D Ring $7.00 – $9.00 Stainless Steel 316 Marine Grade D Ring It doesn’t matter if you are using the D ring for your self made freediving lanyard, bag or freediving buoy. It is essential that the materials are sea water-resistant and of high quality. And this is precisely what these D rings are. These D rings are made of high-quality marine grade stainless steel 316 material, have a beautiful finish, and at a price you can’t beat.