All balls are 14” in diameter, impact absorbing and moisture resistant. The casing is sewn from 18 oz. fl exible vinyl coated polyester. The casing design and construction insures that the implement remains dimensionally stable and balanced. The trade secret and craftsmanship utilize the casing to retain the various fibrous cores under tension so that each ball regardless of weight has the friendly feel and will absorb high velocity impact. Each ball carries a 2-year warranty against stitch and lacing failure.