Although kettlebells can be made of different materials and coatings, generally speaking, a kettlebell I usually a cast iron ball shape with a handle on the top that you can carry, swing and grip. Think of a cannonball with a handle and you should get the right kind of picture! This unique design, as distinct to a dumbbell, means that the weight is not evenly distributed and this delivers instability, creating counterbalance and the need to really focus on your core while training with this piece of equipment. They range in weight, are compact in design and also portable too.\r