13815 Brand new and high quality Great for a game player Your palm will not feel any tired even if you used it consecutive over a long time. Easy to install and simple to use Key quantity: 5 Working mode: optical Resolution: 1000dpi Service life: 5，000，000 times Rated voltage: 5V Interface: USB Cable length: 1.2M Support Windows 2000/ME/ XP/Vista/Win7/Mac OS X 10.2 or later versions 1 X optical mouse