Studio Pro Circle and Strip Maker Designed to hold razor knives, marking pens, pencils, glass cutters, for a versatile multi-purpose tool Rigid metal measuring bar with precise laser engraved markings provides accurate measurements to the 1/16 inch Non-skid pads on the circle base keep it securely in place while marking or cutting Make or draw circles from 3" (7.6cm) to 24 1/2" (63 cm) in diameter; Make or draw strips 5/8"(1.6 cm) to 12.25" (31 cm) wide Includes: Strip base, circle base, 1-calibrated (SAE and Metric) brass bar, 1 turret holder with steel wheel turret, and detailed instructions