In my old reliable Kenmore, I used metal bobbins inserted into a removable case. There was no top or bottom to the bobbin. In my new friend a H/V, it takes a specific bobbin that are extremely expensive. Thought I was going to choke when I went to the store where I bought the machine at and saw they were selling them in a package of 10 for $15.00. I have since found them online in packages of 30 for $10.00. The one thing that was important to get used to is the bobbin will only fit on the winder with the "H" logo facing up. Since this is a drop in type, it can only be inserted with the "H" up. (Yes, I tried to put it in upside down on purpose, and it don't work)