Selvage Trimmer tool trims off the factory selvage so that the sheet can be accurately scribed and seemed. When the selvage edge of the material is inserted into the guidance slot, the blade is automatically positioned at the proper distance from the edge for trimming off the selvage. The replaceable U-shaped blade makes a clean, square cut that will be perpendicular to the floor. Simply pull the tool through the material and the selvage is removed. Blades: No. 341 - one each or No. 342 - three each. Net weight: 10 1/2 oz.