One-piece gasket made from durable black urethane rubber. Six sizes to choose from. Fits vintage and classic CHRIS-CRAFT motor boat models built from the late 1930's to the 1960's. 20 inch round and square hatches, oval and rectangle portlights (porthole, boat window) Easy to install. Resists UV sunlight and salt water. Made in Seattle by a classic wooden boat shipwright. See my website for full details and ordering info.-www.StopWaterGasket.com NOTE: Hatches and portlights not for sale, illustration only.