Bought this as a Dealer Demo about 1 year ago, Has approx 200 hours total use. It functions and looks as NEW. It includes all accessories as new. I am including a spare NOS Military grade Rectfier tube as well. You will get the stock basically unused output 12au7 tubes as well. I have the original packing / double boxing. I used this with windows 10 it is immediately recognized and plays flawlessly. Older PC you would need the drivers which are included on the disc that comes with the DAC. No marks or Blems that I can find