Special Features:

Low profile trackball used to position cursor on computer; 3.750 in sq by 1.500 in deep; 2.000 in diameter rotating ball; mfd by penny and giles controls group chicago il

Properties:

A device which includes a sphere mounted in a small open-topped box. The sphere is hand-operated by rotating it in a backward, a forward, or a sideway direction while maintaining the device in a fixed location. The movement of the sphere generates a signal which may be used to move a cursor and/or tracking symbol on the face of a display, such as a cathode ray tube; to input data into an electronic system; and/or to control the operation of a system. It may or may not include additional input devices, such as switches or variable resistors.