Logitech 931477-0403 Nx20 Notebook Optical Mouse Integrated Cord Wrap and Snap  The simplest, most robust cord management system available. The patent-pending Cord Wrap feature enables you to wind the cord neatly into the base of the mouse. All-Terrain Optical Sensor  True mobility means working anywhere. All-Terrain Optical is designed to provide smooth tracking on virtually any surface, in any environment. No ball to clean, either. Shock-Resistant Bumper  Tough, polymeric bodywork is designed to withstand almost any bump in the road. Compact Comfort  Shockingly comfortable for its size, the smooth, rounded shape offers the optimal blend of usability and mobility. Plug and Play  No setup necessary. Plug it in and youre ready to go.