The patented shape supports your hand in an upright neutral posture that generally avoids forearm twisting. Many users including medical doctors ergonomists and physical therapists said the Evoluent Vertical Mouse provides superior comfort and even relieved their wrist pain.Features. Comfortable and easy to use.. Adjustable optical sensor.. Improved thumb rest.. Dimension - 5.5 x 4 x 3.5 in.. Item Weight - 1 lbs.