Kettlebells are one of the oldest pieces of exercise equipment around. If you look up pictures of old-time physical culturists and strongmen from the 19th century they could often be seen with different types and shapes of kettlebells. Modern kettlebells look like a cannonball with a handle. They are unique that their offset center of mass creates loading patterns that are sometimes different from barbells and dumbbells. I have sizes that range from 5lbs to 106lbs and everything in-between. You will utilize various sizes kettlebells depending on which exercise you are doing.