Ceratech ACCURATUS 3331 Mouse - Optical - Cable - 3 Button(s) - Black - USB - 400 dpi - Scroll Wheel - Symmetrical. The Accuratus 3 button optical wheel mouse comes with both USB & PS/2 connection. With its "soft switch" mechanism and centrally mounted scroll wheel, the 3330 series is easy to control and a joy to use. Ideal for left or right-handed people the Accuratus wheel mouse is a great "all rounder".