Includes three replacement blades for the Crain Seammate doorway seaming tool. Each blade has one 23″ long razor sharp edge for scoring the carpet’s backing at the location of a doorway seam. When used with the Seammate, it marks a straight line on the carpet’s backing which can be trace cut with a knife. Blade dimensions: length: 23.27″, width: .560″, thickness: .020″.