Midas-Link Wireless Optical Foldable Arc Mouse 2.4Ghz Adjustible Folding Nano USB Receiver Mice For Notebook Laptop Computer PC Desktop(black) Plug and Play,active tracking scanning frequency,automatic connection High-speed 2.4G wireless mouse smooth and flexible Works at distance of up to 10 meters Adjustible DPI:600DPI,800DPI,1200DPI,1600DPI Batteries:2 x AA Battery (Not included)