Always Evolving. It wasn't easy to improve upon the class-leading design and function of our D3 helmet, but we made it happen. Built with an aerospace shell design and materials, we were able to get the D4 Composite helmet to 1050 grams without sacrificing any strength. MIPS C2 system is used to add an additional layer of coverage. For comfort, the D4 Comp routes cooling air through a front air intake system that flows through the polymer center and power grid side mesh keeping your head cooler during the ride. X-static and XT2 padding keep the inside of the helmet a much nicer place to be. Not intended for use with motorized vehicles.