Material: This inflatable seat cushion for surfboards and kayaks is made of nylon, offering good elasticity and sturdy stitching. It's designed to withstand the rigors of water sports. Waterproof and Sweatproof: Our seat cushion is waterproof and sweatproof, making it sturdy and suitable for all your surfing or kayaking adventures. Easy Installation: The kayak seat is easy to install and remove as needed,which is suitable for both beginners and experienced water sports enthusiasts. Product Dimensions: The backrest measures 46cmx54cm while the seat cushion itself measures 48cmx35cmx17cm, providing ample support for comfortable seating during your water activities. Package Includes: Each package comes with 1 canoe seat cushion,which is easy to install and carry around. Specification: Material:Nylon Size Chart: Seat cushion:48cmx35cmx17cm/18.90inchx13.78inchx6.69inch Back cushion:46cmx54cm/18.11inchx21.26inch Package Includes: 1Kayak Seat Note: Please allow slightly errors 1-2cm differences due to manual measurement.