The mouse we use generally has three keys, left and right buttons plus the middle scroll wheel, which is enough for general use. However, in cases where special purposes are needed, it is obviously far from enough, such as playing games. In addition to having the general keys of a regular mouse, this mouse also has 12 extra buttons on the side, just like the number keys on the keyboard. Moreover, the functions of these 12 buttons can all be set through a program. Using such a mouse to play games will surely be more enjoyable. Game enthusiasts can hurry up and buy one; it currently sells for $80 abroad.