Scotty Rail Mount - Fits 7/8"" & 1"" diameter round rail, and 1"" square rail. For all Scotty post mount rod holders. Works with No. 241 side / deck mount. Fits 7/8 in. and 1 in. diameter round rail, and 1 in. square rail; For all scotty post mount rod holders; Works with no 241 side / deck mount; Includes stainless steel fasteners;