Incredible cushioning at an almost impossibly light weight, so you can protect your knees and be super fast. Ultra-lightweight no-sew SpeedFrame construction upper delivers long-lasting comfort. Full-length HIP CMEVA midsole for shock absorption and an inherently stable ride. Meta-Rocker midsole geometry, specifically engineered with a low heel-toe differential and a sculpted outsole radius in the heel and toe, creates a unique fulcrum effect and encourages a guided foot gait cycle to support a runner's form, and encourage a continuous positive gait speed roll from heel-strike to toe-off. 4mm heel-to-toe offset. Strategic high-abrasion rubber zones on the outsole.