Our design team developed this kettlebell specifically for cross training. How to choose your KETTLEBELL Choose the weight of your KETTLEBELL according to your physical abilities. Start with a 4 kg weight while you learn the right technique. Combine muscle strengthening and cardio training! KETTLEBELL workouts give you more strength more power but also more flexibility and resistance. Versatility Offers a complete workout.Combine muscle strengthening and cardio training! Durability Ultra-durable rubber base, protects floors against knocks. Ergonomic grip Wide, practical handle for gripping with 1 or 2 hands depending on the exercise. Our design team developed this kettlebell specifically for cross training.