[Adjustable] - It is adjustable, can be large or small, and can be opened and closed by simply turning the ring [Premium Material] - Made of high quality Metal, , not easy to rust, good hardness, high strength [Professional Adjustable Circle Drawing Tool] - The circle drawing tool is a math ruler that easily creates a in seconds and the drawing tool not easily move during use and the drawing, is flexible and convenient, and can be reused for many years. [Easy to use] - The diameter becomes larger with clockwise rotation and smaller with counterclockwise rotation. It is very easy to use. [Multipurpose] - The round template ruler tool is a great tool for students, carpentry. Also perfect for engraving, carpentry, sewing, sewing and lifting., Manufacturer: Jnchdghwa