IOGEAR 2.4 GHz Wireless On-Lap Keyboard with Optical Trackball and Scroll Wheel GKM581R (Black) Ergonomic Wireless 2.4GHz Keyboard with Built-in Optical Trackball, Left/Right Buttons and Scroll Wheel Features 2.4GHz Technology Offers Greater Wireless Range Up to 33 Feet Away from Your Computer/Home Theater PC Built-in Left and Right Mouse Buttons with Built-in Scroll Wheel Built-in Optical Trackball with 1000DPI Perfect Solution for Digital Living Rooms or PC to TV