2.4GHz Free moving in 10 meters 16 automatically switchabel working frequency and over 60.000 groups of secure encoding to free external interfere Nano super Mini receiver. Plug-and-Play Built-in storage medium,no need re-code after you replace battery Resolution frequency（800-1200CPI）conversion Color：silver material: plastic Built-in Mini receiver design Power On/OFF function Energy saving technology.2 pieces of AAA alkaline battery supply over 3 months working time. Low-Voltage alarming function Operation be affected greatly due to using environment Battery life be different,depending on personal habit of using mice Specifications: Power Supply: 2 x AAA Batteries (Not Included) Mouse type: Wireless Optical Mouse Interface: USB Button: 5 Buttons + 1 Scroll Wheel Resolution: 800 to 1200DPI Supports: 2000/XP/Vista/ME Size: 3.94 Inch x 2.36 Inch x 1.38 Inch (L x W x H) Weight: 4.09 oz/Set Rated working Voltage:3.0V Rated working Current:15mA Package includes: 2 x 2.4G Wireless Mouse 2 x Mini Receiver Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.