The 4-Sided Replacement Cut Bar is designed for the Fiskars 12" (45mm) high-capacity rotary paper trimmers (replacement cutting bar protects the rotary blade's cutting edge to provide a long, dependable cutting life). This bar measures 13.5" and has four cutting surfaces. It can be rotated 8 times to maintain clean and accurate cuts. Included is one bar that is easy to install and replace. The instructions are included with the package.