NOW DISCONTINUED-NOT FOR UPLOAD Oliver 25 Series 6" Leather Smelter Boots (25299) Heat-resistant and flame-retardant leather upper stitched with flame-resistant Kevlar fiber thread HS Dual Density Nitrile Rubber Soling System combines a soft, shock-absorbing, low-density air rated rubber midsole with a high-density, durable rubber outsole 25 Series outsole is heat-resistant up to 572 F (300 C) and resistant to chemicals, mineral oils, acids, alkalies, animal fats and oils Meets ASTM F2413-11 M I/75 C/75 Mt/75 EH; Electrical hazard rated outsole, external metatarsal guard Recommended use: heavy metal