I have used this bobbin now for a few years and all I can say is that it is a great tool for me. I can also say that they stand behind their product I could not keep the one's tension very good so on a whim I emailed them with a picture of the bobbin and a short description of what was going on. I wanted them to tell me what I could do, thread lock etc. Or could I buy a part. What I got from them was, what is your address. They shipped me not one but two new tension knobs and said if that did not fix the problem to let them know. All at no cost. these were years old, used, I expected to pay something. So, they stand behind their product.
