The Logitech Trackman Marble Trackball Mouse T-BC21 910-000806 is a versatile and reliable pointing device that offers a unique trackball tracking method for precise cursor control. With a maximum DPI of 300 and side-to-side scrolling features, this mouse provides a comfortable and efficient user experience. The red, gray, and white color options add a touch of style to any workstation, while the PS/2 and USB connectivity options ensure seamless integration with various devices. This deadstock new/sealed product from Logitech is a great choice for those looking for a dependable trackball mouse.