Features: 1.Stable Transmission: This vertical computer mouse adopts 2.4G wireless technology, which provides 10 meters stable transmission and low delay. 2.Powerful Engine: This vertical computer mouse possesses powerful optical engine, which ensures quick response and accurate control. 3.Ergonomic Design: This vertical computer mouse features ergonomic design that reduces muscle strain, wrist pain, keeping your hand and arm in a more comfortable position. 4.Adjustable DPI: This vertical computer mouse supports 3 levels adjustable DPI (800?1200?1600DPI), and easy to adjust and position. 5.Plug and Play: This vertical computer mouse is equipped with USB receiver and it supports plug and play, providing more convenience. specification:Item Type: Vertical Mouse Material: ABS Color: Black Connection: 2.4G Wireless Connection Wireless Frequency: 2402-2480MHz DPI: 800-1200-1600 DPI Buttons: 6 (Left, Right, Wheel, Forward, Backward, DPI Switch) Battery: 2 x AAA Battery (Battery Not Included) PackageList:1 x Vertical Mouse 1 x USB Receiver