The Ironman Train Insole incorporates Spenco’s Total Support® Technology and the patent-pending 3-POD™ Modulation System. This unique combination of cushioning and stability is ideally suited to the demands of training. Unlike the disposable sock liners that come with your shoes, IRONMAN® TRAIN Replacement Insoles use better materials and technologies that cushion, stabilize and support right out of the box. The also promote a more efficient, healthier stride.