Only Certain Snow Boots Available with the OC System.OCsystem®: the innovative, internationally-patented non-slip system.Our non-slip system increases grip, helping you walk comfortably and keep a firm footing on icy surfaces.OCsystem® is built into the soles of your shoes during the production phase.The system features stainless steel studs and a framework created with special, flexible polyurethane that is durable at even the most extreme temperatures.