Caterpillar boots are made for today's hardest working men who need to stay comfortable while on duty. Welted construction for strength and durability. Rated ASTM F2413-11 and are non-metallic and undetectable in electronic security environments. Waterproof – Keeps the wet out with waterproof leathers and using seam sealing or waterproof liners. Extreme Slip Resistance - SRX provides ''best-in-class'' slip resistance, exceeding industry standards and reducing the risk of slips and falls in the workplace. Material: Leather.