The mice were all physically very similar with a rectangular shape and buttons on the top surface. Each had the weigh of the mechanical tracking ball moving positioned in the rear of the device. When moving the mice, the users did not rest their Their fingers on the top surface. fingers grasped one side with their thumb placed on the opposite side. : Hodes and Akagi, Study, development, and design of a mouse\n The rate of movement of the mouse is nearly maximal with respect to the information processing capabilities of the eye-hand guidance system\n