Cast of 356 aluminum alloy and shaped for tremendous strength and uncompromising stiffness, NRS Oar Mounts will hold up for a very long time. They're the most versatile oar mount around. You can adjust their working height by rotating them around the circumference of the rails. These oar mounts stand 8" tall. Accepts 5/8" oarlocks or pins and include mounting hardware. Fits over pipe 1 5/8" in Diameter. Single mount does not include bolts.