The Boiler Gauge, manufactured by Nivelco® is an industrial pressure gauge that measures pressure steam, designed with a brass material in a black heavy duty casing with a 1.0% accuracy, a 1/2"bsp or 3/8" bsp connection AND comes in a wide variety of standard ranges. It is also available in different dial sizes including 12" (300mm), 10" (250mm) and 8" (200mm).