Tested and working . The Logitech Trackman Marble T-BC21 810-000767 USB Mouse in Gray and Red is a trackball mouse with a maximum DPI of 400. It features programmable buttons and wired USB connectivity. With a sleek design and compact dimensions of 2.0 inches in height, 6.1 inches in length, and 3.2 inches in width, this mouse offers a comfortable and efficient pointing experience for users. The trackball technology provides precise and smooth cursor movement, making it a reliable choice for those looking for a different style of mouse.