Volt Spark v1 FGConcave's minimalistic, lightweight Volt Spark boot has been meticulously created from the finest materials. Our one piece upper material is made up from thermo fused engineered materials, consisting of several layers of high end soft touch synthetics, contributing to optimum comfort and durability. The side wings based at the rear of the boot on both lateral and medial sides, in conjunction with a nylon heel counter, provide superior stability that