AMERICAN BUILT with materials from around the world. Left and right asymmetrical steel toes. KEEN.Dry waterproof, breathable membrane. KEEN.Web-Tech abrasion technology. TPU shank for midfoot support. Lining with hydrophobic/hydrophilic 2-zone comfort technology. Cleansport NXT(TM) for natural odor control. Meets ASTM F1677-96 MARK II non-slip testing standards. Meets ASTM F2412-11 and F2413-11 M I/75 C/75 EH standards.