Amazon.com | RefrigiWear Men。Comfort Rating: -40°F to 10°F ASTM F2413-24 I/C EH SR rated composite toe The BOA® Fit System for micro-adjustable fit that won\'t come loose These cold-weather work boots have a waterproof 6-inch nylon and leather upper and these winter work boots fight fatigue with VitaComfort®, which absorbs the shock to your feet from walking and standing all day. Each boot has an ASTM composite safety toe, RefrigiWear® Hybrid Traction outsoles, and rubber heel plates for added protection and extra durability in all types of frigid working conditions. The boots are also electrical-hazard compliant for added safety. Long, hard days in tough conditions won\'t knock you down. Stay on your feet all day in extreme comfort.