Don't discard old rotary blades, use them in the BladeSaver Thread Cutter! Product Features: Give your used 45mm rotary blades extended life by using them in the BladeSaver Thread Cutter and make cutting your chain pieced fabric projects fast and easy. Each BladeSaver comes with a magnetic case to keep your thread cutter safe when not in use or when taking it to class. The BladeSaver case doubles as the blade stand to hold your thread cutter securely in place during use.