This is a Logicool ERGO M575S wireless trackball mouse. I'm selling it because I haven't gotten used to it after owning it for about six months. The main body is in good condition. Please refrain from purchasing if you are sensitive to items that have been stored at home. [Brand] Logicool [Model Number] ERGO M575S [Included Items] Main unit, AA battery (partially used) Thank you. Logitech ERGO M575 Wireless Trackball M575S (Black) Brand: logicool Mouse/Trackball Type: Trackball Cable Type: Wireless Number of Buttons: 5.0 buttons Optical Resolution (dpi): 2000.0 dpi Mouse/Trackball Features: Ergonomic, DPI switching, Receiver storage, Side buttons Color: Black, Gray Weight (g): 145.0 g Battery Type: AA