From what I understand these are for hearing aids, but there may be other uses for them. I actually just got these in the mail today. I had signed up for them quite a long time ago. I searched for them but I can no longer find the original post. Maybe my memory is wrong, but I think I ordered these for my grandma’s hearing aids, and she died in Nov 2006. So, either I remember wrong, or it has taken 1 1/2 years for them to send them to me!