1.6-1.8 mm water resistant suede upper with high tenacity nylon mesh. GORE-TEX Sierra lining for moisture wicking and breathability. Asoflex 00 SR lasting board. Lite 2 anatomic footbed. Matrix outsole with Active Heel Support technology. Weight: 640 g (size 8.5, 1/2 pair). Matrix technology: ; A moderately aggressive, dual-density outsole that incorporates Aso-brake for maximum downhill traction and offers superior grip on uneven terrain. Active Heel Support: ; Visual technology that's created by externalizing the mechanism positioned in the heel zone. Optimized by the use of leading-edge materials that offer lightweight support, shock absorption, and full heel control. Measurements: ; Weight: 1 lb 9 oz ; Circumference: 13 1 2 in ; Shaft: 6 1 2 in ; Product measurements were taken using size US Men's 9, width D - Medium. Please note that measurements may vary by size.