Made for Perception and Wilderness Systems brand sit-on-top kayaks, fits any scupper hole 1 inch to 1 1/2 inches. Use to plug the scupper holes in your sit-on-top kayak. Prevents water from coming into the cockpit (good for cold water), but also prevents water from flowing out too (not so good for rough water). Easy to use. Made of soft rubber-like material. Sold in pairs. 2 feet of Bungee Cord is suggested as a tether. The small end is 1 inch, large end is 1.5 inches. (Alt part numbers 8023060 - 8025053 - 8023779) Sold as a Four Pack.