Terra X4 Powerstrap - special Gravel performance shoe with non-slip outsoleThe Powerstrap X4 is a versatile, gravel trail-focused shoe designed for riders whose adventures and ambitions take them beyond traditional paved roads. The Terra X4 with Velcro system gives extra support and stability due to its own unique construction. While most traditional Velcro fasteners only pull two sides of the upper together, the Powerstrap configuration wraps a strap around the foot and uses only two straps to provide a secure fit. The instep and midfoot are separately adjustable to ensure a customized fit and compression. For these versatile shoes, fizik has developed a special outsole with an optimal combination of stiffness and comfort: an outsole made of a mixture of nylon and carbon for targeted stiffness and a rubber tread for effective grip and durability on natural, alternating surfaces. And all this in the elegant look of a street bike shoe - the Terry X4 Powerstrap is 100% Gravel!