Rocky Boots 6173 work boot is its Rocky Waterproof construction. It combines a waterproof inner layer with the upper providing a barrier that helps keep water out and feet dry for an exceptional comfortable boot. It comes with the comfort feature of its contoured removable polyurethane cushion insole providing direct underfoot cushion comfort. The polyurethane material used in its insole is known for its cushioning while not bottoming out features. Some open celled foams feel very comfortable to the initial touch, but will tend to break down faster than a product made with polyurethane. Plus, it is extra thick in the heel contact area. This provides additional underfoot comfort to the wearer. In addition to meeting the highest ASTM F2413-05 Impact and Compression standards, Rocky Boot 6173 also complies with its Aprroved Xtremium Toe standards. This type of work boot is made with insulating bottoms providing secondary electrical hazard protection to those areas dealing with open circuits under dry conditions, but also can be worn in work areas requiring only basic protective toe work boots.