Truly Windproof
Although textiles like microfibers, closely woven fabrics, and many fleece materials are often considered windproof, even light winds can penetrate most of these fabrics, making you feel chilled and uncomfortable. In technical terms, a fabric can only be considered truly windproof if its air permeability is 1.0 cfm (volume of air that passes through one cubic foot of fabric in one minute) or less. All GORE-TEX® products meet or exceed this standard.