This is a rather large hanger, and will not print at 100% scale on most common printers. (maxed out my MM2 horizontal build area). The hanger dowel for 100% scale should be 1.25", so scale according to what size dowel you are hanging the carrier on to.
Technical
The hanger is flat on the bottom, with concentric circular cutouts to eliminate peeling off of the build plate due to warping. The ends of the hangers have internal cutouts to maximize strength.