Alvin Q404A drafting compass features synchronized precision "scissor-action" thread system allowing you open or close legs to desired radius in one quick motion. Drawing compass is perfectly balanced and weighted for easy one-hand operation. Draws circles up to 14" diameter. Durable nickel plated zinc construction in silver. Spare needle point and 2 leads included. Alvin Q404A 6" quick-action drafting compass is quality-made in Germany.