This is a vintage airplane vacuum suction gauge. It is in nice condition considering its age. I think it might be military so it would be nice to own a little piece of history. There is a brass identification tag attached to the back of the instrument, but due to age it is difficult to read. However, I did find another guage that looked almost the same with the same part number/ PN 0311957. Despite its nice condition, I have to sell it “as is” since I have no way to check its function. The actual unit has no major damages and the glass on the front is clear and undamaged. Zoom in close to check out its condition. I ship by USPS PRIORITY MAIL and only within the Continental United States. Thank you for looking.