Chango S-2000

2-in-1 board (rocker and wobble) improves balance and stimulates muscles. 4" center ball is for aggressive training, 3" ball for beginners. Same benefits as R4 model, with increased tilt angles. Use for calf stretch, push ups, or sit on it and wobble. Uses 2 center balls for 2 levels of wobble. Balance on the large yellow center ball, or remove the yellow ball and balance on two wooden balls attached to the bottom of the board. Excellent sports trainer. Features: Balance on the yellow center ball and it's a wobble board, remove the yellow ball and balance on the two wooden balls and it's a rocker board. The platform is handcrafted of laminated wood and measures 15"L x 7 1/2"W The board can also be used for calf stretches and push-ups. Size: 15"L x 7 1/2"W Options: Advanced 4" ball included (S2000) UPC: 714905090775 Beginner/Advanced 3" and 4" ball included(S2000BA) UPC: 714905090768