Outer boots: made from particularly tear proof kangaroo leather velcro fastener for different calf sizes two plastic sliders at places subject to particular wear highly elastic areas at instep & heel abrasion resistant PU foam padding for long durability special racing sole with extremely rounded heel plastic sole abrasion resistance (screwed on) Inner boots: aramid/plastic hard shell shock-absorbing padding four layer shinbone protection shock-absorbing insoles in the calf & heel areas robust plastic hard shell with hinged joint aramid/elastic stretch zone anatomically formed spherical heel bed triple aramid-reinforcement left in toe area forefoot reinforcement sweat-absorbing leather lining