Welded in to a vessel or a pipeline, these rugged fitting provide either flow or level indicator. They are available in carbon steel, Stainless steel and special alloys. Obround visible glass sizes range from 1 to 4 inches in width and 6 to 24 inches in length and are suitable for ASME code requirements. Rectangular sight-glass fitting are available with a 5/8-inch wide view and up to 70 inches in overall length. Custom designs are also available.