The Aku Viaz GTX Men's Hiking Boot is designed for use under reasonably heavy loads on rough hiking trails, rugged alpine ridges, and via ferratas. The upper, made of soft and supple suede, incorporates Aku's Air 8000 technology for unparalleled breathability when you're humping a load under the Dolomite sun, and it sports a Gore Tex Performance Comfort waterproof membrane to keep your feet dry when, in the course of 17 seconds, dark clouds roll in, obscure said sun, and start turning the trail into a river. Regardless of trail conditions, the Viaz's sticky and tough Vibram Nepal outsole will keep you from slipping around like a deer on a frozen pond, and the speed lace hooks make it easy to dial in the right snugness. If it ended there, the Viaz would be a killer boot, but it doesn't. Aku's real party trick is the fit. The Viaz features the IMS 1 Precise Internal Midsole System, if you're keeping score to help you achieve the perfect fit, with an internal micro EVA layer on top of a super thin nylon lasting board which together provide the stiffness to conquer rugged terrain and the softness to keep your foot from slipping and banging around inside your boot. To top it off, there are interchangeable IMS 162 and Orthoform 150 footbeds, which you can choose between depending on the volume of your foot. If there's a more precise hiking boot out there, it's hiding itself pretty well.