The unconventional animal-like form of NAO's original Digigrade stilts is recaptured and upgraded in this next-generation design. By employing a 4-bar linkage mechanism, the stilts acquire a spring-loaded flex wherein the foot of the stilt pivots like a real foot, in proportion to the angle of the upper stilts, which themselves pivot 25 degrees about the wearer's ankle. The net result is a softer, more cushioned stride, improved balance, and a bit of spring in your step. And of course you'll just look really cool in them. All-aluminum frame, with rigid leg guards.