U.S. Gauge Co. N.Y.  Pressure Gauge 5" Black Dial 800 PSI  1/4 AD 8784 I don't know anything about this gauge other than it is labeled as last tested in 12/22/1944?, It has a glass face and I think it is made of a hard plastic.   It has scratches and signs of rust, Offered as pictured. please see photos for more details and size, We have more please visit our store, Thank you