I have a 103 model vest machine. the older, little bigger kind. I have two. I used one that I kept at home, and one that I used in college. It was nice to have an extra so I didn't have to haul it back and forth. It would also be nice if you are a divorced family and want to keep one at mom or dad's. It is free if you want it. Would love to give it to someone who could use it! I just had a double lung transplant and no longer need to do vest treatments. I live in MN.