70036 Yardstick Compass-Lead & Pin Post

This thing is pure genius. Makes drawing large circles a breeze and you’re only limited by the size of your ruler. I use it for self-drafting sewing patterns.It was a little too narrow to fit over my wooden yardstick, but it attached to my metal one perfectly. Even though my metal one is much thinner than the slot on each post, when you twist the knobs down to tighten, that’s plenty to hold the posts snugly in place.