PRECISION MATH COMPASS - Designed for mathematical geometry and art drawing. Features a unique design to help prevent slipping during use. PRECISE ADJUSTMENT - Equipped with an adjustment knob for accurate geometric constructions. Compass can be locked in place for consistent performance. ADJUSTABLE SIZE - Draws circles with a maximum diameter of 10 inches and a minimum diameter of 1/8 inch. Suitable for a variety of circle sizes. ALL-METAL CONSTRUCTION - Made from durable metal materials for long-lasting use. Includes three spare leads for easy replacement. STABILITY - Features a spring bow design and thumbwheel to help prevent unintended sliding. Color: Black Material: Metal Package Contents: 1 x Precision Compass 2 x Spare Screws 3 x Spare Lead Note: The package includes only the items listed above. Other items are not included. Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement may vary by +/- 1-3 cm.