Inland Wireless Multimedia Keyboard with Trackball (70142) 2.4GHZ digital wireless communication- available within 9m and high anti-interference capability Integration of keyboard and mouse makes more convenient and faster operation optical-sensor trackball controller, exact and frequent and position Wheel scroll technology, randomly turn between two directions. Flat and comfortable key design Wheel scroll technology, randomly turn between two directions, Integration of keyboard and mouse makes more convenient and faster operation Optical-sensor trackball controller, exact and frequent and position Smart power indicating lamp Multilingual supporter 2.4GHZ digital wireless communication- available within 9m and high anti-interference capability Key life circle: Over 5 million times