The modelcraft circular compasses cutter measures and cuts out circles as big as 150 mm in diameter the sharp long lasting steel blades are easily replaceabledesigned to accurately cut out paper card masking films leather vinyl and more simply unscrew the top of the ruler and adjust the placement of the cutter before sealing it againrest the pin on your material and turn the top gently but firmly letting the cutter run through the surfaceradius from 10 mm to 150 mmruler included for