Exustar SR4102KB Carbon Road Shoes. The Exustar SR4102KB Carbon Road Shoes are engineered for high performance. The shoe features a carbon fiber nylon composite sole that delivers exceptional stiffness while keeping the weight low. The sole also features strategically placed vents that provide cooling comfort for warm weather riding. The synthetic leather and mesh upper is bonded, rather than stitched, for weight savings and comfort. The microlock ratcheting buckle and dual Velcro strap retention system ensures an optimal feet while the molded heel cup prevents heel slip.