LS2 Stream II Lux Full FaceLS2 Stream II Lux Helmet The LS2 Stream II Helmet features an aerodynamic, sport styled shell made from LS2s proprietary Kinetic Polymer Alloy (KPA). KPA uses nanotechnology to blend microscopic aramid fibers with a high end polymer and allows for amazing energy managing performance with managed flexibility that absorbs energy without the ricochet effect of inferior materials. The Stream II meets the ECE 22. 06 rotational energy management