Unlike neoprene, the Gill Speedskin is breathable, so it offers day long comfort on its own in warm conditions or as a snug thermal layer in colder weather. Made from a stretchy 3-layer soft-shell fabric with a fleece backing, the material is waterproof, breathable, and wind resistant. The ergonomic cut of the Speedskin is designed to fit close to the body without impeding movement. An excellent choice of layering for protection in cool weather. Clickhere to see the Gill size chart.