Features: 2.4G wireless transmission, 10m transmission distance, stable and fast connection. Powerful optical engine provides accurate click, quick response and stable signal. Ergonomic design, fit the palm, delicate hand feel, comfortable to use. 3 adjustable DPI(1200-1600-2400DPI), meet your daily office and gaming needs. Compact and lightweight, equipped with USB receiver, plug and play, convenient to use. Specification: Brand: YWYT Model: G839 Button number4 Tracking system: Optical Connection mode: 2.4G wireless Effective distance: 10m DPI: 1200-1600-2400DPI Battery: 1*AA battery(not included) Working voltage/current: 1.5V/7mA Supported system: Windows 98/2000/ME/XP/Vista/Win7/Win8/Win10/Vista Mac OS Item size: 10 * 6.3* 3.8cm /3.9 * 2.5* 1.5in Item weight: Approx. 55g /1.9oz Packing list: 1 * Mouse 1 * USB receiver