The World’s Strongest Golf Umbrella! Built with a multi-patented frame and wind vent technology, The Square Challenger 68 boasts a 68” arc (PGA size), enhanced FlexTech fiberglass double rib frame, and safety glide opening mechanism. With its unique elastics stretcher along with internal cutouts and anti-slip rubber handle with medallion, this umbrella can withstand 75mph winds. Also powered by our patented RainAlertz app, telling you when it’s going to rain.