Our 12" Rubber INSULATED Calk features a full lace-up front that provides support and stability. For Warmth, a layer of 3mm felt is added to the inside of the boot. The double layer of rubber in the foot and heel area prolongs the wear of the boot. Handmade from all natural rubber, this boot also features a steel shank, rust free eyelets and an arch support for comfort. Replaceable calks were added to provide outstanding traction in wet and snowy conditions.