These were acquired from a Craigslist seller who stated "smoke-free home". Of course, when I got there his father-in-law was smoking. So, I've aired these out, and there is still a faint* smell of smoke on the headgear, tube, mesh bag, and carrying case -- and a particularly noticeable smoke odor on the silicone on the masks. I would assume his father-in-law lives in the house. (Seller says he used CPAP 3 times before opting for surgery -- found data for one night of CPAP machine use in late 2013.)
Why would you want these?
-you want to experiment with the boiling baking soda method -- or are paranoid about Ozium -- and want to do a trial run with either technique or are pioneering a new cleaning technique and need test masks
-you are building a smoky-CPAP kit for the times you will be in smoky environments
-you need props for your indie film
First image: "L" ResMed Mirage Quattro mask, headgear has stains which are pictured to the left of the forehead adjustment knob; ResMed headgear size Medium

Second image: Respironics tube; faint smoky odor

Third image: "L" Respironics ComfortGel Blue Full face mask; Respironics head gear (no size label)

Fourth image: Respironics mesh bag and mystery part which has been identified

Fifth image: Respironics carrying case for System One; note dust (?) on flap and dirt on strap; similar dust line on bottom of case

Will entertain offers via PM.
(*Faint odor = you sniff clothes that you've been airing out in the sun after being in a smoky bar, and you think they need a little more time in the sun or you consider washing them because that might be faster -- that's the level of the odor) (Smoke odor on silicone parts is more noticeable.)