The Scotty Rail Mount Adapter is designed to fit ⅞” and 1” diameter round rails, as well as 1” square rails, providing versatile mounting options. Compatible with all Scotty post mount rod holders, it works seamlessly with the 241 Side/Deck Mount (sold separately). The adapter includes stainless steel fasteners for secure installation. When used with a 1” square rail, ¼–20 x 2” round head stainless steel machine screws (not included) are required for proper attachment.