Genuine U.S. Air Force and Navy issue sunglasses are manufactured under military specification MIL-S-25948H.andolph Aviator SunglassesGenuine U.S. Air Force and Navy issue sunglasses are manufactured under military specification MIL-S-25948H. They screen out harmful UV rays giving you 98-100% UV protection. They’ll give you distortion free, glare free, prism free vision in true neutral grey color. They’re tough too. Impact and scratch resistant, they come in 23-carat gold, matte black or gunmetal with 52, 55, or 58-mm lenses. Carrying case and microfiber lens cloth included.Military Issued: HGU4/P, MIL-S-25948HWhich Size Do I Wear?Not sure if a 52mm, 55mm, or 58mm frame is right for you? Here we will show you how to tell which frame will fit you best.Looking into your mirror hold a ruler so it is lined up with each temple. Measure in inches the distance between your left and right temples.