Never heard of such a model. Since you’re saying they’re used, I’d guess that someone didn’t properly modify their description to 1, 3 or 5, i.e they were using a template.

I would be extremely suspicious of these devices. They could be PLAY:1s, they could be Sonos Ones, etc, but you wouldn’t know what it really was until you purchased it. If the seller can’t properly list what they’re selling, it’s hard to trust them.

Hey Paul, if it’s labeled with something like Play:X and not the proper model number, it’s a preproduction unit, likely from a beta test.

Assuming that it’s a beta unit, officially speaking, we make no guaranties about the continued functionality of beta units outside of the original beta program. They don’t have any warranty, and while they might work perfectly fine for years, they also may not function at all. Beta units units aren’t meant to be sold after the beta program is over, especially as the original tester didn’t pay for them in the first place, and was allowed to keep them or maybe got them some other way, like finding them in an e-waste.

Yes, Ryan, that’s it.  The units do have “ DVT build -- property of Sonos" on the bottom.   While I already own a few “property of Sonos” units (demos that had the power port drilled out and subsequently repaired) the price on these isn’t worth the risk for me.  Thanx for confirming my suspicions...

DVT is a term used in hardware development, see https://www.quora.com/What-is-the-difference-between-EVT-DVT-and-PVT-in-engineering-validation-tests