Kensington's line of trackball products has earned the largest number of awards in the industry's history. That's because of Kensington's commitment to combining the best hardware with the most up-to-date software features. Now, by matching easy-to-use software with a new 4-button design, the best just got better. ??The new Expert Mouse allows you to get more fingers in on the action. In addition, its flexible, symmetrical trackball design fits any size hand.