❀Features a screw for exact diameter control, delivering professional levels accuracy for circles of all sizes. ❀The polished surfaces ensures smooth operations and consistent results every time. Ideal for drafting, measuring, and precisions work. ❀Simply rotate the top rings to open/close and adjust the diameter (clockwise to enlarge, counterclockwise to reduce). ❀Create perfect circles in seconds without complex setup required. Perfect for quick sketches or detailed projects. ❀The circular designs allows frees size adjustments to meet various drawing needs. Without extra tool needed.