Justin Nagelberg uses the Sa umbrella in New York City. By replacing the metal skeleton with two canopies, the design is lighter and has more headroom. Courtesy of Justin Nagelberg hide caption toggle caption Courtesy of Justin Nagelberg All Tech Considered Weekly Innovation: An Umbrella For The Modern Age October 22, 2014 • The developers of the Sa say it's almost impossible to blow inside out. Based on origami, the umbrella's design replaces the metal skeleton with two canopies that expand and retract in unison.
