The resilient, battle-hardened CDI™ sunglass has a long track record of saving eyes and lives in hostile situations. The ESS CDI's U.S. MIL SPEC* high-impact lenses can be easily exchanged for quick adaptation to your environment. Its high-speed low-drag frame and shatter-resistant lenses make the CDI™ comfortable and cool enough for downtime yet functional and rugged enough for the battlefield. Medium fit. The CDI's Lateral Exchange System™ makes interchanging any of the seven available lens colors quick and easy.