Our NEW model 880 with the new ATOP exterior lace system makes lace tension an easy task. Turn the knob for increased lace tension and pull the knob to release tension. Durable stainless cable runs through 3 sets of nylon guides for a secure fit and correct heel placement. A stiff polymer shell for strength is bonded to the exterior Polyurethane, together forming a durable and stiff flex to quickly transfer power to your edges. Integrated liner. Upper is made from lightweight laminated nylon and Polyurethane.