A new extreme-cold iteration of our base layer expertise, the Bullet proof has been designed to be worn between a traditional next-to-skin baselayer and an outer shell to offer maximum thermal protection for minimal weight. At the heart of the Bullet Proof’s performance is Q36.5’s proprietary Air Insulation, an ultralight fleece constructed from brushed mesh to create a surface that captures a large volume of air (the world’s lightest insulation!) between layers, as well increasing surface area in contact with the body, thus facilitating the wicking of moisture, keeping you dry for longer!