Weighted stability ball! Lift it, shift it, shake itntogether the ball and the weighted material create dynamic resistance and audible feedback, With 21/2 lbs, of unstable weight inside it, this stability ball won"t roll away when you"re exercising, You can perform traditional stability ball exercises plus design new exercise sequences, It"s a total-body training tool that"s more versatile than a traditional stability ball, Customize the size by inflating to 55 cm or 65 cm, 6 unique designs on the ball"s surface provide points of reference for exercise techniques and cueing, You can even use it like a medicine ball, Color: Translucent blue, SKU: PWSS845