The Mini ball is 10 inches in diameter, impact absorbing and moisture resistant. Made with the same casing as other quality Dynamax balls, The 18 oz. flexible vinyl coated polyester is made to last in any gym setting. The casing design and construction insures that the implement remains dimensionally stable and balanced. The Dynamax 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. This ball carries a warranty against stitch and lacing failure.