Light and flexible is the name of the game here. A lot of mesh for breathability and Charged Cushioning® to help protect against impact. Just put them on and run for miles. "Engineered mesh upper is extremely lightweight & breathable, with strategic support where you need it Foam padding placed around your ankle collar & under the tongue for an incredibly comfortable fit & feel Comfort sockliner molds to your foot with padding in the heel for ultimate cushioning at heel-strike Charged Cushioning® midsole uses compression molded foam for ultimate responsiveness & durability Tire inspired outsole pattern provides ultimate flex & superior traction Style #: 3025244 Offset: 8mm Weight: 8.2oz Imported NEUTRAL: For runners who need flexibility, cushioning & versatility"