With this 3.5 update, the Olympus received minor updates to the upper. It features a new, more durable upper fabric pattern, but otherwise retains the same attributes as the 3 to make it a flexible, stable shoe. With the addition of InnerFlex™ as well as a 3mm reduction in stack height the midsole both flexible and responsive, and when paired with a widened platform and grooved outsole, provides excellent stability on uneven terrain. Vibram® MegaGrip® rubber sculpted in the Altra TrailClaw™ pattern, continues to provide the traction needed for a variety of surfaces.