FULL-GRAIN POLISHABLE LEATHER & 1000 DENIER NYLON UPPERTo reduce the weight of the boot, we combine our smooth, full-grain leather with incredibly strong 1000 Denier nylon. This durable upper is completely polishable.GORE-TEX (GTX)100% waterproof and breathable, GORE-TEX liners ensure that no water gets in, while allowing sweat and moisture to get out.EVA MIDSOLEKnown for its lightweight properties, EVA is a special polymer that provides excellent cushioning.VIBRAM® STRIKER® TORRENT OUTSOLE360° pentagonal low lug pattern grips in all directions, a flex notch design adds flexibility in key pivot areas and a more rugged outer lug pattern sheds water and provides maximum surface contact.EXTENDED SIZESTo accommodate more people, we've made this boot in extended sizes. We recommend women select 1.5 to 2 full sizes down for correct fit.DANNER TFX-8 PLATFORMOur lightest weight and most versatile TFX construction featuring a cross-stitch design for added durability and stability in the lateral toe and media heel pivot zones.HOW IT FITSThe 851 last is an update to our popular 850 last. This last fits true to size with an athletic and supportive fit while providing ample room in the toe. Offering a specific heel shape that locks the heel in place for better fit and comfort on the back end of the boot, this supportive fit is ideal for those needing high mileage performance from their gear.