Mouse does the job. I travel a lot with notebook on the go and do not want me to verenken the finger on trackball. Off switch is handy conserves battery. Unit is robust, is stuck with me in the Aktentache and has endured all trips. Lids for covering it could be fixed. Comes with all surfaces clear except clear glass. Good value for money. For me, the size is just right: not too small, so that your mouse fits comfortably in the hand, not too big, so it takes up too much space.
