The Singer Featherweight 221 thread cutter was the only thing on the machine that did not work very well. This new thread cutter is extra sharp and easy to use. It sticks to the chrome face plate on your Featherweight, so there is no chance of it harming the finish. It also doubles as a bumper dot to keep you from damaging the finish on your bed extension by hitting the screw that holds on the faceplate.