One of the primary benefits of using the dual Incra track is that it has a built in tape. This tape is also easily adjusted in its track. In order to take advantage of this feature, I needed a cursor to read the tape. This cursor is just a piece of scrap that holds a bit of Lexan with a scribed line in it. The cursor is attached to the Rat chassis with a single small bolt. This is one of the most beneficial accessories for the Mortise Rail.