Was this a production device? I don't recall it at all.
Yes, it shipped at the same time as the original iPhone, and was pretty much gone by the 3GS era.
I still own one of these though I'm not sure why (I use AirPods). It was a pretty good BT headset for its time (which is a major qualification). I was always afraid it would fall out of my ear so only used it indoors.
Speaking of weird Apple iPhone accessories: I also own a 30-pin iPhone radio adaptor which I used to use while commuting.
Wait till you see the original homepod.
the big D-battery speaker ??
The iPod Hi-Fi! I still have one of those. Though it’s connected to, also defunct, Chromecast Audio for multi room audio setup. Here’s someone reviewing the speaker: http://www.minimallyminimal.com/blog/apple-ipod-hi-fi