The CAT Tread Safety Glasses have three lens inclination adjustments with snap-lock ratchet mechanism, 2.2 polycarbonate material tested at Velocity to shield from impact, Crystal clear Optical class 1 lens recommended for continuous wear, fog prevention coating, hard coated both ...The CAT Tread Safety Glasses have three lens inclination adjustments with snap-lock ratchet mechanism, 2.2 polycarbonate material tested at Velocity to shield from impact, Crystal clear Optical class 1 lens recommended for continuous wear, fog prevention coating, hard coated both sides for resistance to scratching. The frame has flex temples with an integrated cushioning system, neck cord attachment facility, upper and lower eye protection, vented for air flow and fog resistance, soft touch vented nose piece.