Product Description: Designed for Comfort, Folds for Portability. You take your notebook PC everywhere. That's why the Arc Mouse is designed to go with you. Expanded, it's a sturdy and comfortable full-sized mouse. Folded, it fits perfectly into your bag. Overview: You take your notebook PC everywhere. That's why the Arc Mouse is designed to go with you. Expanded, it's a sturdy and comfortable full-sized mouse. Folded, it fits perfectly into your bag. Features: Folds for Portability Designed for comfort, the Arc Mouse folds to 60% of its fully expanded size, with the folding motion controlling turning the mouse on and off. Micro-Transceiver Snaps into the bottom of the mouse. Battery status indicator Changes color to indicate when the battery needs to be replaced. Additional Features: 2.4 GHz wireless with up to 30-foot range Laser tracking 4 buttons Carrying case included System Requirements: Windows Vista/Win7/Windows XP or Mac OS X v10.2–10.5 Powered USB port 2 AAA alkaline batteries