Most compact, light yet quality feel, precise pointing, functional buttons, a 'free-wheeling', high quality feeling micro-gear wheel mouse, subtle rubberized thumb cutout, fit INSIDE your palm , super directional, super quality feel in every aspect. Have had it for 10+ years and the half dozen or others since instantly get replaced by it because they are too large/klunky/not 'pro' feeling, smooth, etc,etc,etc as the Revolution MX is......one guy asking $440 on Ebay for one lol...