Saucony Kilkenny XC 4 Spike 100% Synthetic and mesh Rubber sole Designed for cross-country racing in distances ranging from 3k to 10k on rubber or grass surfaces CMEVA midsole for lightweight durability Open mesh upper for lightweight breathability Slip Lasting involves wrapping and stitching the upper in a bootie-like shape before it is glued to the midsole to increase flexibility and decrease weight XT-600 is located throughout the outsole and is a carbon rubber material that increases traction without sacrificing durability.