Now here's a rare look at an uncommon item!
This is the "Sonic X-Treme Stereo Cassette Player". And it is pretty boring. (Isn't that wierd?) As you know, a few items were released with "X-Treme" branding on them, even though the game never was. They were meant to help promote it when it came out, with items like a book, magazine, stickers and...apparently this tape player walkman like item. However, the clamshell plastic packaging is about the only 'Sonic like' thing about this sad item. It's just a generic looking "80s-90s" type plastic tape player with hot green 'blast' shapes & some yellow accents with ridges. There are no Sonic images or themes, just a cheap looking stamp of the logo on one side.

This looks like some last-minute slapped on branding, and likely didn't sell well and so is rare. The list of features includes the ability to 'fast forward' (as if that was a feature and not just standard...) then "Sonic" stereo headphones (note: has nothing to do with Sonic except that they emit sounds) The inset shows the back of the item, & headband part, it's just black. The package front has the 'neon outline' sports Sonic that only appears in relation to anything Xtreme. Here, he's on a snowboard looking back over a shoulder. Because of it's inability to sell well, the fact that the game it's branded for never came out, and the last minute slap-on look of the device, this is uncommon but still pretty interesting to take a look at. 

 (duplicate from SonicGear merged so potentially same info below)

Now here's a look at something REALLY rare!
It's a Sonic X-Treme Stereo Cassette Player! (So, a portable walkman type tape music player with headphones) To make it even rare-er, it's here mint in the clamshell style package. Remember, Sonic X-Treme never came out as a game, but a few merchandise trickled through anyway--and it always had that 'neon line work' for Sonic doing something they think is 'xtreme'. In this case, it's him doing a trick on a snowboard.
You can see a few other xtreme branded things around on Gear, but because the game got cancelled, nearly none of it had a good release and the majority was canceled before it even came out. That's what makes an entire branded tape player even more unusual. The colors & design are very nearly 80s in their fashion...and the actual "Sonic" branding on it is very small...was this originally a generic item & they added a Sonic sticker & packaging? Did it have another element of design anywhere else? Is this a packaged prototype or did a few of these actually get out? This is a very rare and interesting item, so be sure to save the photo for yourself.