• Bally hinged doors are the strongest in the industry, with a heavy U-channel structural steel frame (not plastic or wood) secured with Speed-Loks provide years of reliable tight sealing service. Standard size is 36" x 78" (.91 x 1.98m), with other sizes available to 60" x 84" (1.52 x2.13m). Traffic doors from Rubbair are ideal for processing and high traffic areas.