DREAMUS&reg; NEW Ergonomic USB Wireless Mouse Vertical Optical Mouse for Laptop Computer Tablet PC Windows 98/Me/2000/XP/Vista/Win 7 Resolution: 800dpi;Dimension: 102(W) X 85(D) X 72mm(H); Button: 4 buttons in default / 1 scroll wheel (middle button); Weight: 200g (include USB cable);Interface: USB (Cable 1.5m/5ft); Operation System required : Windows 98/Me/2000/XP/Vista/Win 7; Colors:Black/Red/Blue/Purple/Gray; (Default is Black,if you want others,pls feel free to contact us.Thanks!)