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 “Super Mable”, Airhead “Pit Stop” and Gladiator “Super Brawler” 3-person towable tube BACKREST ONLY. If you need both the BACKREST and the SEAT BASE Replacement, please see our 3 Rider "Super Mable" Style 2 Piece Replacement Set. Please note the position of the inflation valve in the picture and ensure it is compatible with your backrest. You may need to fill via a flexible hose if your existing valve cover does not align properly! 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 78”W and 30" deep armrests. 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.