You're looking at a leathercraft stencil that allows you to precisely measure rounded corners. Excellent for drawing curved lines and curved cut marks. Especially for belts and the corners of leather.
With this amazing stencil and its precision markings you will be able to trace and cut perfectly rounded corners from as little as 10mm from the centre to up an arc 110mm away, in 5mm increments.
No more awkward guesswork or inaccurate compasses, this stencil will ensure consistent results every time.