America’s Best Selling RoundTop Garage. RoundTop Shelter delivers quality features and value. Every frame is built with high grade steel that goes through a 13 step Rhino Shield Surface Prep process. Heavy duty 1-5/8″ diameter steel frame is bonded with Dupont thermoset baked on powder coat finish that prevents chipping, peeling, rust and corrosion. Triple-layer polyethylene rip stop weave fabric cover is hot air fused at the seams and 100% waterproof.