Trammel-Head-Set-Bar-31mm-Capacity-Faithfull-FAITRAMMEL-p-Faithfull-Trammel-Heads-are-used-to-draw-circles-&-measure-sizable-distances-with-the-accuracy-of-a-divider-Also-for-layout-marking-templates-&-drawing-large-circles-p-p-The-trammel-heads-clamp-on-to-any-wood-or-metal-bar-up-to-31mm-wide-They-feature-needle-point-legs-&-one-trammel-can-also-hold-a-pencil-p-Faithfull-FAITRAMMEL-Trammel-Head-Set-Bar-31mm-Capacity