The Oakley SI Ballistic M Frame 2.0 surpasses ANSI Z87.1 Industrial Standards for high-mass and high-velocity impact protection. Additionally the M Frame 2.0 meets MIL SPEC, MIL-PRF-31013. All lenses are made of pure Plutonite®, a proprietary material that offers the highest level of optical clarity available in eyewear. You get razor-sharp clarity at all angles of view, which maximizes peripheral vision and protection against sun, wind and side impact. It also features a clip that holds the lens and frame together providing more secure support.