The GORE M WINDSTOPPER Base Layer Shirt is a windproof, breathable base layer to wear under other layers to keep your skin dry and warm on cool to cold days. The GORE M WINDSTOPPER Base Layer Shirt is a windproof, breathable base layer to wear under other layers to keep your skin dry and warm on cool to cold days. GORE® WINDSTOPPER® product: totally windproof, extremely breathable and durably water resistant GORE® WINDSTOPPER® insert on front, over shoulders and on kidney area Quick drying material Thin and soft fabric