The Dura-3 is the one of the finest stilts available. Great innovative design concepts and technology. Features: Steel inserts at the adjustment screw location and field replaceable nylon leg sleeves. Heavy duty screw on replaceable soles are mounted on "super tough" nylon floor plates. Replaceable nylon bearings at leg connections and lock nuts on hinge bolts give extra wear and longer stilt life. Snap-in nylon sleeves separate the telescoping legs and steel inserts prevent adjustment hole wear. Ankle movement is made possible with a direct spring activation method which also provides individual spring adjustment for forward and rearward motion