Size “L”. This is one tough piece of gear. I used it on a fiberglass Current Designs Solstice GTS sea kayak with a cockpit of about 31″ X 16.” I’m 5’9″, 170 lb, medium build. Bring your boat to check the fit. Hand made in Durango, CO (The company ceased production in 2016). Photos available. Located in Shelburne, Mass.