Microsoft Trackball Optical 1.0 PS2/USB Compatible (X05-87475). Ball included. The Microsoft and symbol are pretty much worn off and there's other normal wear for its age and usage but its fully functional and in overall really nice shape. I plugged this into my personal computer and as you can see from (pics #12 and #13) it works. I actually used it to create this listing. 

Please look at pics to see what you are bidding on before bidding thank you!

Also check out other GREAT items in my store including my other trackball mouse listing.

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