The vertical mouse is : ergonomic mouse WirelessWhen the user is using the mouse, the palm is close to the desktop and the vertical state. Ordinary mouse in the course of the use of the user's arm is to move in the horizontal to control it, a long time to easily lead to fatigue of the arm, and even lead to serious parts of the arm joints, long-term use of ordinary mouse computer work May also be due to a small mouse and suffering from occupational diseases. We also call it Ergonomic mouse. M618 plus with led light , m618 without led .The material of m618 plus is matte feeling , when you use m618 plus , it is more comfortable .The dpi of m618 is more suitable for office using .M618 plus is bigger than m618 . Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.