I've seen some shockers on Sonos; they're only small so probably get knocked a lot, the metal grill is hard to clean and depending where it goes can get splashed if near a sink or... by other stuff, plus pets/kidsFor a phone a grade C would be full working order but cosmetic damage like scratches. Speakers tend not to move around much so not sure how you would even get one in poor condition unless it was carried around by someone doing a lot of traveling.