Check the listing for details. Circle Master Compass circle drawing, drafting, art work for school or shop work. Condition: Used. Listed at 12.99 USD. Use with marker, pen, pencil, or razor knife. Knurled center nut makes precision adjustment easy and holds the setting. Draw circles of variable diameter (12 inches typical maximum diameter) depending on the length of the pencil and stylus used. Only one has the printing of "Key Curriculum Press" all others have printing of "circle master compass PAT.# 3,537,181". All are in good working order. Some have darker lettering with slight fading but all of them are readable with no missing prints.It has a hole in the disks to align them to each other and hold in place if needed or the hole can be used as a key chain if a split ring is added in the hole (ring not included).Good for a shop or art class.These do not come with stylus or pencil. Volume purchase discounts are available.