Sedici Close Thermic Base Layer Long Johns are designed to keep the rider warm and dry on those really cold days. The unique combination of two performance fabrics help create the perfect base layer. The Close Thermic outer layer is a tri-layer laminate that blocks incoming wind while a semi-permeable layer allows perspiration vapor to escape. The four way stretch fleece underneath traps heat against the body while molding to the rider for excellent mobility. While the Sedici Close Thermic Base Layer Long Johns were designed with riders in mind they will perform equally as well in any situation where extra warmth is needed.