The Threadborne Slingflex is not just for runners but also gym devotees and it’s got a few more bells and whistles to it that justifies the slightly higher price tag in comparison to the Micro G Assert. First off, this shoe is constructed out of a knit fabric, not mesh. And this is no ordinary knit: it’s made of a fabric called Dyneema that is marketed as the strongest fabric in the world. This is the stuff that the military uses for its personal protection vests and that metalworkers use for protective gloves and a version of it makes up the overlay of this shoe. Knowing this makes it seem pretty fierce, doesn’t it? Meanwhile, the midsole cushioning is made up of Under Armour’s patented 2-layered Charged Cushioning System. One layer provides soft support while the second, denser layer provides stability. Lastly, the outsole has solid rubber on high impact areas while softer, blown rubber makes up the rest, reducing weight but maintaining traction on any surface from a treadmill to wet city streets.