Our replacement innertubes are quite simply the strongest in the business. This is a Bladder Replacement for models like the Sportsstuff “Big Mable”and the Airhead “Pit Stop” 2 person towable tube SEAT BASE ONLY. If you need both the BACKREST and the SEAT BASE Replacement, please see our 2 Person "BIG MABLE" Style 2 Piece Replacement Set. This contains the innertube only, and NOT the cover. Breathe new life into your towable! Dont spoil that summer vacation by having your favorite towable "fall flat"! Have an affordable spare with you on your well deserved time off! 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.