The Oakley SI Ballistic M Frame Alpha Replacement Lens was designed to provide maximum protection while on the job. The lens contour maximizes your field of view and provides extended impact protection on the side. This lens meets MIL PRF 32432 Ballistic Impact Standards, ensuring it is approved for wear on active duty in the US military. The M Frame Alpha Replacement Lensfits SI M Frame Alpha and SI Halo platforms for interchangeability between glasses and it also blocks 100% of UVA/UVB/UVC up to 400nm for visual clarity. Order these replacement lenses today!