The 3M Lexa standard welding glasses are made of polycarbonate, are packaged 20 per case, come in shade 5.0 black and meet ANSI Z87.1-2003, CSA Z94.3 standards. Proper sizing is important when buying this product. The size for this product is Medium. These types of items are designed for specific applications which feature ways of safeguarding & shielding itself and/or the user. This product is designed and manufactured such that it offers the following protection: Anti-Fog, Impact-Resistant, Scratch-Resistant, UV-Protective. Provides 99.9 % of UV Protection.