The guide is a tracking devise that attaches to the Max to assist reading in a straight line. It snaps onto the max and has four tiny rollers that allow you to move the max smoothly, and in a straight line for reading across the page. You can order from any EVS reseller.
Shipping is extra.
Clarity is excellent. The MAX product is made by Enhanced Vision Systems. Cables are also included. Slip it on the mouse is very easy to do. You and a friend.