Thru-hull scupper with nut is used for mounting through the transom. Manufactured from molded white polymer, the thru-hull scupper features an extra long length to allow mounting on a 2-1/8" thick surface. Soft black flapper. For use with 1-1/2" hose. Flange diameter: 2-7/8". Mounting diameter: 1-7/8". Nut and mounting hardware included.