It allows for different widths, which allows for adjusting seam widths to customize and allow for alterations. Allows me to trace and add seam allowance right at the same time. Works fine as well to do embroidered applications.

It's well-made, so it firmly holds the moveable wheels when they are repositioned. This works so much better than the 2 pencil trick. Love this tracing tool.

While i wish this had one serrated and one smooth wheel, this works well. This tool makes it easy to note the stitching line and the cutting line. I hunted down recommended waxed tracing paper and my life sewing life changed.

Tracing wheels are wobbly in their shafts, and the lines were never parallel. The legs or stems that go from the tracing wheels into the handle are super flimsy.