Ergonomic design slim trackball offers comfortable operability. - Brand: Kensington - Model Name: SlimBlade Trackball - Compatible OS: Windows, Mac Thank you for viewing. This is a listing for a Kensington SlimBlade Trackball. I purchased this as a clearance item at an electronics store around this summer, but I haven't used it and it has been stored unopened at home. It has a 5-year warranty, but I assume it's probably invalid. (I didn't receive a warranty card at the store.) I'd like to sell it to anyone who wants to use it.