The most significant feature of the Lehigh Safety Shoes Unisex Steel Toe Rubber Hydroshock Dielectric Waterproof Work Boot is that each boot is hydroshock tested to 2500 volts DC with less than 5 micro amps of current leakage. A key comfort feature of the 3149 is 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 F2413-11 Impact & Compression standards, Lehigh stock # 3149 also complies with its Electrical Hazard 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 in addition to its hydroshock properties noted above. Plus, it also can be worn in work areas requiring only basic protective toe work boots.