Bionic Body Soft Medicine Ball Weighted Slam Wall Ball for Cardio Workout and Core Training – Ideal for Squat, Lunge… $33.99 – $59.84 Make sure this fits by entering your model number. SIZE VARIETY FOR CUSTOMIZED WORKOUTS – The Bionic Body training ball comes in 6, 10, 14, and 20 lb. varieties, making it perfect for any training program. Every ball size has a 13-inch diameter. HEAVY-DUTY CONSTRUCTION – Featuring a durable yet soft surface, this versatile gear is engineered to withstand the force created when dropped on hard surfaces. The multi-stitched structure ensures that this toning ball will not easily lose its shape.