The world's strongest folding umbrella! Our Folding Challenger III is now made with eco-friendly rPET polyester. This auto open umbrella has unique elastic stretchers and internal cutouts to allow greater air flow. The Folding Challenger III has a multi-patented metal frame, fiberglass ribs, and built with wind vent technology – made to endure tough weather. This umbrella is powered by our patented RainAlertz App, telling you when it's going to rain.