The Exersit is also an exercise device, which can be used in much the same way as full-size exercise balls are (but without the risks of falling off the latter may pose to some much older, younger, or less stable users). It's great for helping to strength core muscles, and for improving posture, which can relieve the strain many of us place on our backs and necks from slouching (it functions similar to a sitting wedge, in this respect).
You can also stand on this cushion, to get the massaging benefits from its nodules on your feet, or sit on it on the floor and incorporate it into your other exercise routines, as you do squats, leg lefts, or yoga stretches, etc. In either case, with continued use, your core strength will improve, as the balancing cushion leads you stabilize your body while performing a range of different positions.
You can also use it as a "wiggle seat," to help occupy children with lots of nervous energy.
Although at about 13 inches in diameter and 2.5 inches deep, it is an easily washable cushion which could go on virtually any kitchen, dining, office chair, or stool which you may otherwise find too hard to sit on for very long. You can also use it in a pillow case to match the decor.
The cushion comes pre-inflated, but if it deflates after leaving it in the cold too long or if you want to adjust its pressure, there is a valve insert so you can re-inflate it using an inflation needle and a pump (not included).
This cushion was previously marketed as the Exer-Sit Cushion Stretch Disc (since it could be used as a companion to stretching exercises).