Fly at the speed of sound in the Mach 16 cross-country spike from Brooks! ; An ultralightweight cross-country racing flat. ; Ultralightweight synthetic uppers. ; Asymmetrical lacing for a glove-like fit. ; Lightly padded tongue and contoured heel cup for added comfort and performance. ; Full-length compression molded EVA midsole offers lightweight cushioning. ; Ultrathin rubber outsole delivers lightweight grip and durability. ; Five-spike configuration delivers the ultimate in traction. ; Imported. Measurements: ; Weight: 5 oz ; Product measurements were taken using size 9, width B - Medium. Please note that measurements may vary by size.