This 18" compass rule set includes the shaft, anchor point, lead holder and lead all in one package. Make circles up to 36". Automatically gives radius, area and circumference. Adjust circle size with fingertip control. Calibrations are in inches on one side and metric on the other. Made from the highest quality aluminum for ultra smooth edges and a solid feel without flexibility. The anodized finish gives a satin like feel, while the photo anodized calibrations are permanent and will not clean or rub off.