Polar BUFF® is composed of a seamless tube of Thermolite® sewn to a tube of Polartec® fleece fabric. This combination of fabrics helps to combat heat loss and maintains body temperature in extreme cold environments. Product certified according to the UNE-EN 14058:2004 standard, which classifies it as a PPE Thermal Resistance Class 1 product (UNE-EN 31092:1996/ A1:2013) and also as belonging to Air Permeability Class 1 (UNE-EN ISO 9237:1996).