Specifications: Connection Type: 2.4GHz wireless connection Wireless range: 10 meters Connect / Power: Yes, on/off switch Battery Details: 1 x AA Battery life: 18 months* *Battery life may vary based on user and computing DPI (Min/Max): 1000 Sensor technology: Logitech Advanced Optical Tracking Sensor resolution: 1000 dpi Scroll Wheel: Yes, 2D, optical Number of buttons: 3 Standard and Special Buttons: Middle click