DC Power (TM) Ergonomic Optical USB Wired Vertical Mouse for Laptop Mac Computer Tablet PC Windows , 800 DPI, 5 Buttons. (Red) Brand Trademarks: DC , Record Number: 86526328, more details, please check by uspto gov. Resolution: 800dpi;Dimension: 102(W) X 85(D) X 72mm(H); Button: 4 buttons in default / 1 scroll wheel (middle button); Vertical Optical Mouse for Laptop Computer Tablet PC Windows 98/Me/2000/XP/Vista/Win 7 Back & Forward Button for Convenience: Two Internet navigational buttons, back and forward, are conveniently located on the left side of mouse to provide you with Internet browser control with minimal hand movement.