The body of the flow sight is 303 stainless steel. The glass sight has a pressure tight, solid gasket design with Viton seals. The unit tolerates temperatures up to 300° F. The maximum recommended pressure is 125 PSI. The port diameter is 7/16”. The total height is 2 1/4” and the hex size is 13/16”. The visible area of the glass sight is 1 1/16” in length.