This is the ELECOM wireless trackball mouse, EX-G M-XT20RBK. It features an evolved trackball with reliable basic performance and unprecedented new functions. It's a thumb-operated type with 5 buttons, allowing for comfortable operation. It supports 2.4GHz wireless connection. [Brand] ELECOM [Model Number] M-XT20RBK [Connection Method] Wireless (2.4GHz) [Number of Buttons] 5 buttons [Operation Type] Thumb operation [Item Condition] Junk [Color] Black [Note] Junk item It did not respond even when batteries were inserted. It might work depending on the settings, but I am selling it because I don't use it. Comes with box, instruction manual, and receiver. AA batteries are not included. [Note] Please purchase only if you understand that this is a junk item. Returns and refunds are not accepted under any circumstances. Power Source...Battery-powered Connection Type...Wireless (Bluetooth)