Our Wobble Disc is used for core strengthening exercises, improving balance and for sitting. The 13" diameter is large enough to accommodate 2 feet, but some people buy two discs, one for each foot. The built-in valve allows the height to be adjusted from 2" to 3" high. Arrives inflated for immediate use. Our Rubber Medicine Balls are a great accompaniment. 6-Color set of 6.
