Some years before I retired, a new vacuum showed up at my employer's for use by our custodian. It was a black, round, squat canister machine called a Nilfisk. It had a Hepa filter on it. Well, the custodian(s) trashed it, vacuuming up floor stripper and other stuff. Then they cut our custodian position out of the budget and contract cleaners would come in a couple of hours a day. The Nilfisk was thrown back in a locker in the boiler room and never used again. I'd never heard of a Nilfisk before this one. Recently, I started looking up information on these machines and I was astonished at how expensive they are. What a waste.