You also may want to try the Microsoft Notebook Mouse made by Logitech. I use mine eight to ten hours a day and change the battery around every six months. I turned a lot of people at work onto it and they love it.

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99 ML320
94 SL600
92 SL500
95 E320 Cabriolet
87 560SEC
86 300SDL Grease Car
80 380SLC Euro

13 Fiat Abarth
02 Maserati Spyder Cambiocorsa
00 BMW Z3
90 Rolls Royce Silver Spur
80 Ferrari 308 GTSI
88 Jaguar XJS12 H&E Edition
99 Land Rover Discovery