Heavy Duty PVC Construction (12-15% thicker than any original or replacement tube on the market) Don’t throw away that perfectly good towable cover, re-use it! TRL Watersports original replacement innertubes are quite simply the strongest in the business. This is a bladder replacement for models like the Sportsstuff “Great Big Mable”, Airhead “Pit Stop” and Gladiator “Great Big Brawler” 4-person towable tube SEAT BASE ONLY. If you need both the BACKREST and the SEAT BASE Replacement, please see our 4 Rider "Great Big Mable" 2 Piece Replacement Set. This contains the innertube only, and NOT the cover. Breathe new life into your towable! Don't spoil that summer vacation by having your favorite towable "fall flat"! Have an affordable spare with you on your well-deserved time off! Measurements (Inflated) Approximately 92"L X 106"W If you have any questions on whether this innertube will fit your towable, we will be happy to assist and ensure it is compatible with your cover! Check out our entire line of products available. We have 2, 3 and 4 Rider sofa style replacement innertubes available in complete sets or individual sections.