WPI Yarn Measuring Tool: Oak
A handmade tool for measuring 'wraps per inch' of any yarn. Just wrap the yarn around one of the three spaces (without cramming it too tightly), and count the number of wraps to give you a measure of yarn thickness There's a 1", 1/2" and 1/4" space on each tool.
These tools are hand turned from English oak wood (grown and milled on our own farm), before finishing with a simple beeswax polish.
There are several of these available, so the tool in the first photo may not be the exact one you receive, although it will be very similar.