Brooks PureGrit Women's Trail Running Shoes Toe Flex - A toe box split allows for the hallux to function independently and engage the runner's natural balance. Nav Band - Wraps the instep to comfortably secure the foot in place. Ideal Heel - Brooks' signature inverted heel promotes a natural foot strike. BioMoGo DNA - An earth friendly midsole, blended with Brooks' patent pending DNA smart cushioning creates a springy return. Anatomical Last - Designed from an anatomical form, allowing the shoes to contour the foot for a glove like feel.