This is a set of 5 spacers that are useful when creating mock-ups of ruler work designs on paper.
Each 1/2 inch donut has a central hole that can accommodate a pencil or other standard drawing tool. It will add 1/4 inch to your drawing to account for the distance from the needle to the stitched line. This enables you to accurately simulate the design you will later stitch.
Note that while most ruler feet are 1/2 in in diameter, there are some ruler feet that are 9/16 inch (e.g. APQS, Gammil, etc). We carry both the 1/2 inch and 9/16 inch sized donutz.
Simply remove the paper backing from the backside of your spacer and you are ready to start drawing!