Designed for tough environments and conditions, Monitor’s Radiator winter boots are made of leather and Cordura fabric and have a waterproof and breathable Monitex membrane that makes the boots completely waterproof. The boots are also lined with 200 grams of Thinsulate lining to keep your feet warm and dry. The M4 Boa lacing system makes the boots easy to put on and take off. The insole is a Monitor SS2.0 sole in 2 density polyurethane. The midsole is made of polyurethane and the outsole in heat-resistant nitrile rubber.