I was looking for a large hard medicine ball. I just it for thoracic mobility and back stretching exercises. I needed an 11" diameter. Weight did not matter. My gym had one but the brand they had was 20lbs and cost close to $100. That same brands 18lb ball was only 9.5" diameter. I was skeptical that the Titan 12lb med ball would be 11" diameter since the could I've seen are usually the size of a basketball (9.5"). Got it today and am extremely happy. Gave it a bunch of pumps of air to make it hard. Measured the circumference (34.75") which translates to a diameter of 11". Thank you Titan for giving me what I was looking for for $30 dollars with quick free shipping.