Airman 1st Class Ryan Joplin, 380th Expeditionary Operations Support Squadron aircrew flight equipment technician, checks an oxygen mask for an F-35A Lightning helmet June 26, 2019, at Al Dhafra Air Base, United Arab Emirates. The mask prevents hypoxia symptoms by providing sufficient oxygen levels the pilot would need at higher altitudes. (U.S. Air Force photo by Staff Sgt. Chris Thornbury)