I made a film roll keychain with a 5 yen coin. The 5 yen coin is a perfect fit for old Japanese film camera battery compartments. Plus it is lucky too. If you would like one, I will make one just for you. Check out the stuff page. It is it very limited due to my time and the number of used film rolls I have. The make of the film is not guaranteed, due to what I have in my bag of tricks.