Altra EGO™ midsole foam for a smooth yet responsive ride along with Slim FootShape™ for a snugger fit that is designed for natural movement. Midsole - Altra EGO™. Outsole - FootPod™. Cushion - Moderate. Stack Height - 26 mm. Upper - Breathable Engineered Mesh. Weight - 8.8 oz/ 250 g.