Product details:

SPRI Ultra Ball's superior performance and maximum durability help make it the safest and most reliable stability ball on the market today. It's made of a heavier, thicker-gauge material than other balls, so it's more resistant to stretching or deforming and ideal for use in the most demanding club environments. The dimpled surface offers a 360-degree body-traction effect. Slow deflate up to 600 lbs.