Lighter than ever, at only 6.7 ounces - the Feather 2 lives up to its name. Its a lightweight training shoe that translates directly into a faster pace. UPPER: Air mesh for maximum breathability. Seamless SprintWeb design for support fit. MIDSOLE: Foam insole for cusihoning with adiPrene+ for forefoot propulsion and efficiency. SprintFrame for stability and speed with a lightweight running chassis. OUTSOLE: adiWear rubber for durability. miCoach compatible. WEIGHT: 6.7 oz.