I bought this unit along with several other items at an estate auction of a retired Dentist. I don't know how long he was retired, but we were told this Unit was working at the time of his retirement. It is Clean and all the Glass lens and dials work, so I imagine it does work, but because of the Odd 5 prong Plug, I can't test it, so it is being sold as is. I'm sure this would be an expensive item if purchased today, but I'm no Dentist, and I know I never will be one, so I am listing it cheap, so anyone just starting out in Dentistry, hopefully this will help you out, and be a good deal for you. It has wall mounting holes on back, and the unit is in good well taken care of condition, but it needs a cleaning.