This inflatable seat cushion with backrest is designed for kayaks and surfboards. Package includes 1 seat cushion with backrest. - Easy installation: Install or remove as needed for a quick setup, suitable for both beginners and experienced paddlers. - Durable PVC construction: Inflatable cushion with strong stitching built to withstand water sports. - Precise dimensions: Backrest 17.72 x 15.75 in; seat cushion 15.75 x 17.72 x 4.33 in for stable, comfortable support. - Benefits: Adds back support, reduces fatigue on long trips, and stores compactly when deflated. - Compatibility and use: Fits most kayaks and stand up paddleboards with standard seating; portable for storage and transport. - Practical scenarios: Long kayak touring or fishing trips; stand up paddleboard sessions needing extra back support; shared gear in rental fleets or multi craft setups.