Two 19-gauge 0.63' U-shaped double riveted cross braces add extra strength to the frame. Features 19-gauge 0.88' round tubular frame with 2.5' frame strengthener. Electromagnetically welded seat back. Single hinges on each side for added stability and durability. Color coordinated polypropylene glides and V-Tip plugs for added stability. Powder coated frame. Tested by Bureau Veritas to support 500 lbs static load capacity.