This tool is specifically used for trimming large stacks of paper such as text blocks, and makes a clean cut through a stack of paper up to 1 3/4" high and a maximum length of 17" (A3). The unit has 2 clamps to fasten it to a bench or table surface. The blade mechanism runs over a rail on ball bearings. The cutting blade is made of high grade HSS steel and can be moved down the paper by adjusting a knurled nut at the top while cutting. The guide rail is extremely stable and will not bend. It guides the blade perfectly straight and vertical through the paper. The result is a smooth cut without mark which can sometimes appear when cut by machine. The tip of the blade runs into a nylon strip in the worktable which ensures that the blade remains sharp. When the nylon strip becomes deeply notched it can be easily removed, turned and installed again. This can be repeated 8 times before it must be replaced. Two springs support the guide rail and allows it to remain open while the paper is positioned onto the work table. Two large knurled nuts positioned below the work table can be tightened to clamp the paper securely in place while cutting. A graduated (metric) ruler is located on a right angle with the guide rail and acts as a stopper for the paper stack. A parallel guide is attached to the ruler and can be positioned as needed. The cutting blade runs precisely at the edge of the guide rail. After repeated use, the moon-shaped cutting blade can be sharpened with a simple tool (included). Wooden parts are made of lacquered birch plywood and ash hardwood. Overall size: 24.5" x 16.5".