CAT(Cheryl's Alignment Tool) Add on set consists of 4 alignment guides (5/8", 3/4", 7/8" and 1") that fit over the lip on the base and help to create straight and evenly placed layers on a card.
The base plate has 2 open ends so that it works for larger sizes cards also or even a scrapbook page. Each alignment guide has the measurement on the side of it.