Contoured shape is for maximum comfort  and support. The sturdy scroll wheel with rubber makes sure that your  hand will not slip when scrolling. Bundles with value-added functions  such as: Screen capture, TutorPen, Keyboard/Mouse Simulation, 16-in-One  and 4-way Wheel. Extreme quality offer over 5 million clicks guaranteed.  Dust-resistant design prolong wheel life-span.Model：N-70FX / N-70FXSType: WiredErgonomic Design: SymmetricSensor: OpticalResolution: 1200-1600 DPIButtons No.: 7Port: USBCable Length: 150 cmNet Weight:95 g (w/ cable)System Requirements: Windows XP / Vista / 7 / 8 / 8.1 / 10