The Air Jordan 21 (XXI) with White / Metallic Silver / Black colorway feature a simple all white leather upper, and may seem bland at first glance, but the technology behind them definitely make up for whatever they lack in looks. Air Jordan 21 feature a double-overlasted phylon midsole supporting four I.P.S.(Independent Podular Suspension) pods on the outsole. The Air Jordan 21 shoes 'also feature a quilted lining/bootie, which provides a better fit. There is a carbon fibre shank plate in the midsole, as well as an improved I.P.S. technology with interchangeable heel Zoom air pillars or encapsulated air pillars. The Air Jordan 21 shoes were released on June 3, 2006.