Smartfish Technologies, L4200C, Whirl Mini Laser Mouse with Anti-Gravity Comfort Pivot (Carbon) 800dpi Hi-Def Laser Mouse with Anti-Gravity Comfort Pivot Patente Pivot Motion Designed to Adjusts to Your Natural Hand/Wrist Position Promotes Movement and Blood Flow to Reduce Fatigue and Discomfort of other "fixed position" mice. 2.4 GHz Wireless with USB Snap In Nano Transceiver for PC & Mac Ambidextrous Design with 4-Way Scroll Wheel Extended Battery Life (AA Batteries Included) Available in Black, White, Silver, Blue, Red and Carbon Colors