Scroll to smart way: With Signature M650 you will have a precision line to line for documents and a quick scroll for long web pages: and change mode with the smartwheel the appropriate setting for your hand: this comfortable full-size mouse is designed for big hands , for an ideal adjustment Improve your comfort: this mouse gives you long hours of comfort thanks to its contoured shape, to the soft thumb area and rubber side grips that keep the hand adjusted and in its place