U.S. Air Force Lt. Col. Aaron Weaver, 60th Aerospace Medicine Squadron Bioenvironmental Engineering Flight commander, explains how face shield prototypes are attached to safety glasses April 10, 2020, at Travis Air Force Base, California. The bioenvironmental engineering flight, 60th Dental Squadron, 60th Air Mobility Wing Phoenix Spark innovation cell and 60th Maintenance Squadron collaborated to design personal protective equipment for David Grant USAF Medical Center. (U.S. Air Force photo by Heide Couch)