The Infinity 3-in-1 trammel set is a must-have for designing and laying out curves and “stepping off” evenly spaced measurements. This trammel set includes a 24” extruded aluminum rail with a scale marked in both Imperial and metric graduations, a pair of steel trammel heads with brass thumb screws, a pair of steel trammel pins, a cutting/marking knife, and a pencil. When used with both trammel pins you can quickly mark evenly spaced graduations, making it easy to layout bookcase shelves and other evenly spaced measurements. The pencil and marking knife can be used to turn the trammel into a large-scale compass to mark curves and circles up to 48” in diameter. The marking knife can also cut thin materials like paper, cardboard, and veneers.