that it uses a UV-C lamp on the nozzle to basically blast any pests (dust mites, bed bugs, bacteria, etc) with ultraviolet radiation and then suck them into a HEPA bag. That was the case, anyways, with the Halo vacuum cleaner from several years back. I'm not really sure how it works, to be honest. Kinda neat.

It doesn't work, Oreck got slammed when they could no longer advertise the Halo as a dust-mite-killing machine! They still sold them for awhile, just without telling people about that great purple light! I have a Halo, and while the light does look cool, it isn't very effective! I don't even remember if the one on mine worked! The Halo is like a plastic (modern) Kirby, it's big and bulky, but looks cool! If you ever happen upon one, buy it! They're getting rare! I rarely see them now,I remember when the original Halo was still on sale at my local Sears!