Putting you in a more natural position, the 20v6 gives athletes a more ground feel during strength training. A Vibram outsole increases durability and a REVlite midsole provides lightweight responsiveness. The burrito tongue and new asym collar with molded foam allows for a more natural heel fit.our left and right feet may differ in length or width as much as a full size. Be sure to measure and try shoes on both feet, and always buy shoes to fit your larger foot.If your feet seem between sizes and you cannot decide which size to select, we suggest you choose the larger size.