Details The Women's Ultra Fastpack IV Mid has been updated with FUTURELIGHT™ and our FastFoam™ midsole system so you can cover more miles, faster, and with more comfort. Style: NF0A46BV Approx Weight (½ pair): 12.5 oz (353 g) Last: TNF-S13-05H Features FUTURELIGHT™ OUR MOST ADVANCED BREATHABLE-WATERPROOF TECHNOLOGY. At the heart of Athlete Tested. Expedition Proven.™ is the philosophy that authentic athlete insights push our design and engineering teams to propel our products forward. Our FUTURELIGHT™ technology is no different. For the first time ever, we’ve added air permeability to a waterproof membrane. The nano structure of the FUTURELIGHT™ membrane allows air to pass through for better venting and breathability without sacrificing waterproofness and durability. This new nano-fiber structure enabled us to create our most lightweight, breathable membrane to date. An ultra-thin, nimble garment that feels comfortable and provides the protection needed against the elements in the harshest environments.