Brooks Pureflow 4 - Men's The Brooks Pureflow 4 provides a lightweight ride for a wide range of runners. Nav-band wraps over the instep to secure the foot in place and can accommodate different foot shapes with a comfortable, assured fit. Anatomical Last contours the foot for a glove-like feel and provides support for every part of the foot. Tuned Density Midsole better corresponds with gender and weight categories to deliver a custom balance of cushioning that's not too soft or stiff. BioMoGo DNA tunes the cushioning and responsiveness to the specific needs of each and every runner. Omega Flex Grooves enhance the flexibility of the midsole for an effortless forefoot ride while still offering great cushioning and midsole integrity. Toe Flex allows the big toe to function independently for a more efficient push off while preventing roll in. Wt. 8.6 oz.