Sportsstuff Sportsstuff Rockin Mable 3These new Rockin' Mables have all the same popular features of our best selling Mable tubes but feature a convex bottom that provides super fun rockin' action! Rockin' Mables slide effortlessly side to side for even more fun, even at slow speeds. Ride them sitting down or kneeling and they can be towed from either end for endless fun! The big wrap around backrest, soft knee seat pads, and lots of strategically placed handles keep you on the tube, no