Aeromat Elite Power Rope Medicine Ball is designed to improve rotational and core strength with variety of movements and planes of motion. It is made with natural rubber and filled with iron sand. Recommend wearing gloves when perform training. This ball is available in 7 weights that are color-coded: 4 lbs - Orange; 6 lbs - Yellow; 8 lbs - Purple; 10 lbs - Blue; 12 lbs - Green; 15 lbs -Red; 18 lbs - Bronze. Dimensions: - 4 lbs: 7.75"" diameter with 37"" rope; - 6 - 12 lbs: 9"" diameter with 39"" rope; - 15 - 18 lbs: 10"" diameter with 39"" rope. AeroMat is one of the leading lifestyle brands in fitness products and accessories, with a mission of making fitness and well-being accessible to all. The products are crafted with durable natural materials with fine attention to detail.