SWIVEL BOAT SEAT MOUNT: This boat seat swivel is an essential piece of equipment for boaters, providing comfort and versatility 2-PIECE REMOVABLE BOAT SEAT SWIVEL: The bottom half of the swivel mounts to your boat seat pedestal, and the top half mounts to the bottom of the seat BOAT SEAT SWIVEL MOUNT FEATURES: A Quick-release design allowing you to remove and store the seat. Slides on easily. Universal Mounting - 0-degree tilt - swivel allows 360-degree rotation for desired seat positions DURABLE CONSTRUCTION: Boat seat swivel base made from corrosion-resistant materials, these mounts are built to withstand harsh marine environments, providing long-lasting durability and safety BOAT SWIVEL SEAT MOUNT MEASUREMENTS: Swivel boat seat mount dimension of the base: 77-inch (178mm) x 7-inch (178mm). Screw Size: 5/16-inch FIVE OCEANS, 40 Years developing High-Quality Marine & Outdoor Products, Weight: 1.75 Pounds, Manufacturer: Five Oceans