The ESS CDI Terrain Tan Sunglasses with Interchangeable Lenses are the ultimate in military-grade protective eyewear. Tan CDI eyewear features an innovative Lateral Exchange System, which enables lightning-fast lens swapping so you can stay ahead of the curve. Engineered to Mil-Spec standards, these Tan CDI Terrain sunglasses feature clear and smoke gray polycarbonate lenses that exceed ANSI, CE, and OSHA standards.