Veritas trammel set's extremely sharp points let you lay out and scribe arcs and circles as precisely as you might ever wish. One point is eccentrically ground, providing 1/8" micro-adjustment range by simply rotating the point. The heads clamp on any material between 5/8" & 3/4" thick. A trapped pin under each clamp knob insures that the heads stay exactly where you put them on the beam. Either pin can be replaced with a pencil (included). Black anodized clamp heads & brass lock knobs make the set as elegant as it is precise. A snap-closed storage case is included.