COMPOSITE TOE: Left and right asymmetrical, non-metallic carbon-fiber toes, a composite material, offer an unobtrusive fit and are 15% lighter than steel; The Pittsburgh Energy work boots meet or exceed ASTM F2412 and F2413 M I/75 and C/75 Standards COMFORT: Made with KEEN.ReGEN a lightweight, compression-resisting midsole providing 50% more energy return than standard EVA foam for lasting support and comfort WATERPROOF: KEEN.DRY is a waterproof, breathable membrane liner that lets vapor out without letting water in for keeping your feet dry and comfortable; The Pittsburg Energy 6” work boots have a mesh liner that integrates with the waterproof membrane TRACTION: Oil- and slip-resistant, non-marking, rubber outsoles are used for improved traction that meet or exceed ASTM F1677 MARK II and ASTM F2913 SATRA Non-Slip Testing Standards, and meets ASTM D471-06 903# oil and isooctane chemical resistance standards SUPPORT: These boots are made with reflective webbing for additional safety and visibility, a secure fit lace capture system and a thermoplastic polyurethane (TPU) shank for midfoot support that provides structure, stability, and comfort