Northwave didn't pull any punches with the design of the Extreme Tech Cycling Shoe, and it's immediately apparent. One glance at the Extreme Tech, and you'll realize that this shoe is something special. Now pick it up. Yup, that's what 198 grams feels like -- it's the lightest shoe on the market. Northwave built the upper from a single shell of ultralight microfiber to eliminate stitching for the lightest possible weight, the best fit and feel, and virtually no hot spots or chafing. The ventilated carbon fiber soleplate is incredibly thin and boasts a weight of just 60 grams while remaining ultra-stiff for instant power transfer. Extreme Tech shoes are compatible with all the top pedals on the market and, thanks to Northwave's innovative low-profile adapter, can even be used with Speedplays.Northwave used BioMap (Biomechanical Mapping) analysis to design the Extreme Tech Cycling Shoe. Athletes are tested extensively to help Northwave design products that work in perfect synergy with the body's systems. This testing ensures optimal fit, comfort, and performance. Biomap testing contributes to every design aspect of the shoes, including cut design and material selection. What all this translates to are shoes that work with your body to optimize performance.The S.B.S. (Step By Step) ratcheting system provides stable closure that won't come undone or loosen while you ride. It allows you to dial in a precise fit so you can maximize pedaling efficiency without having to deal with hot spots and blisters. Extreme Tech shoes also incorporate Northwave's proprietary Speed Lace Winch System, which allows you to adjust the fit of your shoe while you?re on the bike so you can easily accommodate any swelling that might occur on longer rides. The carbon fiber soleplate is much lighter than other, less costly sole materials. It also allows Northwave to reduce sole thickness for direct power transfer from your foot to the pedal. Ventilation is taken care of by vents at the toe and on the sides of the shoes. The Extreme Air footbed allows air to move under your feet for complete circulation. The Extreme Air footbed is also anallergenic and antibacterial to minimize odors.Northwave Extreme Tech Shoes come in White/black, and Orange/green. They are available in whole sizes 39 to 48 and half sizes 39.5 to 45.5.