ALPINESTARS SMX STREET BOOTSFeatures Durable microfiber upper construction that has superb flexibility and a comfortable feel Ergonomic new forefront boot shape is streamlined to better control and feel of the motorcycle controls Thermoplastic Polyurethane (TPU) shin plate protector is race developed for superior impact and abrasion resistance Lateral Thermoplastic Rubbery (TPR) injected ankle support construction provides superior comfort and impact resistance TPU double