This 1″ Round Rail Rod Holder Base will accommodate your 1″ Round Rails on boat brands like SeaArk, Northwestern, and many boats with 1″ Round Railing. Being made out of pure aluminum, this 1″ Round Rail Deluxe Rod Holder Base is explicitly made to handle the hardest of takedowns while keeping your Rod Holder intact. This Rod Holder base is made to accommodate 1/2″ diameter Rod Holders in Both Right-Hand and Left-Hand Threading. Mounting Hardware is included! Including a 1/4″ set screw for added security.