This is a reproduction bobbin case designed for your Singer Featherweight 221. It would be a good idea to have an extra bobbin case especially for bobbin work.
When you remove a bobbin from the case, be sure to snip the thread close to the bobbin case, so you are not putting undue tension on the bobbin case spring. This is true for all sewing machines.
One thing to keep in mind if you take classes and use your Featherweight in a class setting -- when you leave your machine be sure to remove your bobbin case and slip it in your pocket or purse. They are very easy to remove, and unfortunately, there have been instances where bobbin cases have been stolen while class participants were at lunch, etc. It would be much better to be safe than sorry.
