Jackson Safety 14780 Curv-O-Mark Mini Contour Markers, 8" RadiusModels available mini size for scribing circles up to 8" diameterSturdy friction joints maintain rigidity and accuracy, and are made from lightweight, rustproof aluminum for long wearSoapstone crayon is included. The scribe holder will accept round, square or flat soap stone crayon, pencil or steel point scribeFolding type design - three smallest models will fit conveniently into a shirt pocket