This beautifully polished 316 cast stainless steel rectangular boat scupper flange has been used by many builders, mostly bigger sport fishing boats, as cockpit scuppers. The flange mounts on the outside and has a stiff rubber flapper that lets water out, but keeps it from coming back in. Mounts with 4 screws or bolts (not included). Flapper (included) measures 5-1/2" x 2-3/4".
Overall outside width - 7-7/8" Overall outside height - 3-7/8" Opening width - 5-1/2" Opening height - 2" Mounting holes are 4" apart side to side and 3" apart top to bottom.