Vintage IBM 2 Button PS/2 Mouse Model 13H6690, Cleaned & Tested. Four mice available at time of listing. All cleaned, tested, and will work fine in the manner for which they were intended. If you intend to use them with usb adapters or any other reason they weren't intended for, feel free, but I can't guarantee they'll work out. Purchases will be a random mouse from the ones shown unless specified (by serial shown in pictures) before, during, or shortly after purchase. Any questions, feel free to ask.