For this project, you will need:
1 1/4 inch diameter bolt with coarse threads. You'll probably want the shortest one you can get. You could also use an eye bolt with the same threading.
1 piece of string a little longer than you are tall. The string needs to be a kind that doesn't stretch much.
1 large washer or other small weight. Take a look at the video to see how this works, and then use whatever you have available. One good idea might be something that you could wind the string around.
Take a look at the video
to see how all this is going to work.