sentences:  MSD agents use advanced combat helmets, ballistic protective glasses such as Oakleys, body armor, gas masks, radio transceivers with headphones, tactical first aid kits, ballistic vests, various hydration systems, current-generation night vision goggles and GPS handheld devices such as Garmin 60cx, and other geolocation equipment.MSD agents stay current in military and DSS communications systems in order to remain interoperable with other agencies and military units.Since 2009, MSD has made equipment upgrades based on experiences in the Middle East.