Seaworthy Innovation's patented scupper and wedge combo (P/N: SW1143) is a direct replacment for the traditional scupper (white plastic ring with black rubber flapper). The free swinging polished stainless steel door and hidden silicone seal allows for significantly better performance than a rubber flapper scupper. The wedge component is 17 degrees-- this offsets the boats transom angle which is typically 10 to 14 degrees which allows the door to rest in the closed position. The wedge is attached to the boat by 4 supplied screws. The scupper is then attached to the wedge with 3M VHB adhesive which hides all of the screws for a clean look. All stainless steel used in SW1143's construction is marine grade 316.