COMPOSITE TOE: Left and right asymmetrical, non-metallic carbon toes, a composite material, offer an unobtrusive fit and are 15% lighter than steel; The Synchro work boots for men meet or exceed ASTM F3445 and F2413 M I/75 and C/75 Standards WATERPROOF: KEEN.DRY is a waterproof, breathable membrane liner, keeping your feet dry and comfortable; A mesh liner is integrated in these men’s work sneakers to let sweat out without letting water in TRACTION: Oil- and slip-resistant, non-marking, rubber outsoles meet or exceed ASTM F1677 MARK II non-slip, and ASTM SATRA TM31 material abrasion testing standards; 100% non-metallic for easily passing through metal detectors in highly secured areas CONSTRUCTION: Cement construction provides flexible, lightweight performance while a mid-top design delivers classic sneaker style; Nylon shank for midfoot support; Heat-resistant rubber outsole rated up to 572°F/300°C SUPPORT & COMFORT: KonnectFit heel capture system for a locked in feel and increased support in the ankle area; Reflective webbing for additional safety and visibility