This cutter cuts 12" tiles straight. It provides the accuracy demanded by professionals. The straightness of cut is factory-calibrated to +/-.005" prior to shipment, which is essential for precisely matching edges in pattern work. The cutter also has a self-measuring floor guide for repeat cuts at the wall. Position the floor guide against the edge of the last field tile, then slide the tile to be cut underneath the blade and all the way against the wall. When the tile is cut, the width cut off is automatically the amount needed to cover the remaining subfloor. This cutter also has built-in low-profile blade height adjustment knobs that provide fast and easy adjustment.