You are buying a Hilti DD VP-U vacuum pump for a core drill. The pump is being sold for parts/repair non working. The units turns on and runs. Other than that I could not do any other testing. There is a piece broken and missing from the gauge lens. I do not know if there is anything else wrong with it. You are buying it as-is. Please look at the pictures closely before purchasing. Don’t hesitate to ask any questions you might have before purchasing. I would be happy to answer them.