The Verathon design team later produced the Ranger Video Laryngoscope for a United States Air Force requirement that is now rolling forward into EMS and military use. The Cobalt series of GlideScope then introduced a single-use variant that encompasses weights from 1000 grams to morbid obesity and is successful in many airway syndromes as well. The GlideScope Ranger is a variant designed for use in pre-hospital airway management including air, land, and sea applications. This device weighs 1.5 pounds, and is waterproof as well as airworthy to 20,000 feet altitude. The GlideScope Cobalt is a variant that has a reusable video camera with light-emitting core which has a disposable or single use external shell for prevention of cross infection.