1.3 buttons wireless optical mouse +Mini receiver. 2. This is a suit of mini wireless mouse that completely accords with God's image engineering design. 3. Wireless mouse adopts 27MHZ wireless digital technology. 4. Every channel of receiver has 256 ID; it will not be interfered to use two wireless mice at the same time in a very short distance. 5. Wireless mouse adopts advanced optical orientation technology, wise charging and saving capacity design, 800CPI resolutions, and the life of battery is longer, and orientation is more precise. It can be used on any not reflecting surface. 6. Charger of wireless mouse adopts artificial intelligence design; the battery will stop charging when it is full charged. 7. The compatible systems: Win98, ME, 2000, XP, VISTA 8. The exterior size of wireless mouse and receiver Mouse:88 x 49.5 x 32mm Receiver:49 x 17 x 10mm