Product Description: Quantity: 1 piece Package comes with 1 round center finder compass. Diameter : 200mm. (Ladder does not include center pin, aluminum/steel combinations). Diameter of the smallest circle: 20x2=40mm; Diameter of the largest circle: 80x2=160mm With the laser scale, the round compass in the center finder is clear to read and not easy to dirty or damage.Note: You need to remove the protective film on both sides before using it . The center marking tool is made of acrylic material, the item is eco-friendly and durable with good light transmittance and high definition. The centering/compass is perfect for wood turners, arts, crafts, school projects, rough and finish carpenters or use it anywhere you need to draw a circle. Works on wood, posterboard, plastic, metal, glass, composites and more.