The Philadelphia+ 6 inch with internal metatarsal protection has a 3/4 welt construction and heel stabilizer system for torsion stability, coupled with the innovative KEEN.POLAR TRACTION micro-cleat grip outsole. Left and right asymmetrical, non-metallic carbon-fiber toes offer unobtrusive fit and are 15% lighter than steel. KEEN.DRY Waterproof, breathable membrane. Full-grain waterproof leather. Oil- and slip-resistant non-marking rubber outsole. Electric Shock Resistant (ESR) footwear provides a secondary source of protection incase accidentally coming into contact with live electrical circuits. Internal, lightweight XRD® Metatarsal Guard for enhanced impact protection. KEEN.POLAR TRACTION: Micro-glass fibers create a "micro cleat" effect for increased ice traction. Non-metallic, flexible woven-textile puncture resistant midsole plate - ASTM/CSA certified. 3/4 Goodyear welt construction for enhanced durability and flexibility under extreme working conditions. KEEN LUFTcell dual-density PU midsole, infused with air for weightless comfort.