Almost every shadow-line ceiling job requires field cutting a rabbet in the tile to fit at the perimeter, around light fixtures and around columns. This hardwood Shadow-Line Cutter uses standard knife blades. Two quick passes along the edge; one with the guide on the edge of the tile and blade cutting the face, the other with the guide on the face and the blade cutting the edge, makes a clean rabbet cut. Comes with 1 blade only.