▪ Sole Material Rubber▪ Shaft Circumference 13 Inches▪ Outer Material Rubber▪Closure Type Zip▪ Warming system: 200g 3M Thinsulate keeps your feet warm and dry even when the temperature is -25F. 3M Thinsulate provides about 1½ times the warmth of down and about twice the warmth of other high-loft insulation materials when equal thicknesses are compared.▪ Waterproof material: Men's snow boots feature waterproof construction for waterproof & windproof and synthetic toe caps for anti-collision.▪ Durable & slip resistant: The sick rubber outsole is more stable, slip & abrasion resistant, and flexible in response to various outdoor terrain.▪ Perfect for outdoor & indoor: Designed for both daily life in winter and outdoor sports like skiing, snowmobiling, ice fishing, outdoor party, and so on.▪ What you get: our worry-free warranty and friendly customer service, NORTIV 8 is an American brand that aims at providing high-quality outdoor shoes.