last weekend i was going trough this part of my Walkman collection wich is boxed on the addic, and found this WM-6.

It sounds crisp and clear, but needs a new belt wich i will install oncomming weekend.

I also was wondering if any of you know this Sony-type, cause i could not find anything about it on this forum.

It is an autoreverse device, totaly in plastic, and has some "strange" looking belt- holders on the back of it.

I kinda like it!

I believe the WM-6 and WM-16 are identical.  First affordable auto reverse Sony.  The odd swivels on back are for a shoulder strap.  Do not think it came with a belt clip.  For a budget conscious model its pretty decent sounding.   The WM-11 and WM-22 are the same units.  Unsure of why same players have different model numbers although for Sony usually meant for specific regions of the world.  

Yeah, the WM-6 was a very interesting unit.  It was Sony's 2nd Auto Reverse model after the WM-7.  The most interesting feature being that the heads are at the opposite side of the unit as the transport controls, you don't see this very often.  It was the first walkman to feature cue/review in that you could FF or RW with the play button depressed in order to 'hear' for gaps in the tracks.  A very simple unit but far from budget.

Other Sony Walkmans that have the opposite side buttons and the front loading style Walkmans are R15 and F85.