The Nike LunarGlide+ 4 running shoe provides lightweight support for the mild- to moderate overpronator. Evolved Flywire technology hugs the entire length of foot with customizable, lightweight support. Heel clip engages upon footstrike to provide a snug fit and support. Lunarlon system with "bottomless" carrier construction adds cushioning. Dynamic Support platform offers stability. Premium three-layer sockliner delivers comfort/support. Natural-motion engineered flex grooves promote an efficient stride. BRS 1000� at the heel, environmentally preferred rubber everywhere else. Requires purchasing the Nike iPod Sport Kit (#0001101) in order to make this shoe Nike+ ready. Wt. 9.7 oz.