You've moved past the blunt-needle school compass and need something that actually holds a line. The Mars 551 is full metal with a centre wheel so your arc stays true without re-gripping every two seconds. Spring bow head keeps the legs locked at your chosen radius. One hinged leg joint gives you that smooth, controlled sweep. Universal adaptor means it takes standard leads. Parts box includes two pieces of lead and one needle joint. Draws up to 265mm circles at a 155mm overall length. This is the compass you keep on the desk after primary school ends
