Therersquos a reason why enertor is the only insole worn by usain bolt designed by leading podiatrists and the only insoles to use patented d3o smart material enertor insoles offer the most advanced protection yet against injuries engineered by the experts enertor heel cups help to protect against impact at the heel enhanced by d3o smart material for unrivalled shock absorption and impact protection d3o is a patented smart material that cushions the foot when mov