ISABOB prewound bobbins are made from fine strong 100% polyester thread. They save time and are very economical to use. It is a finer thread and great for machine embroidery and all fine sewing. Pre-wound bobbins can be used in most all sewing machines, both drop-in and bobbin case styles.
NOTE: In some cases, the machine may stop before the pre-wound bobbin is completely out. This is due to the machines electronic sensor not detecting the remaining thread, sensing the bobbin is empty. In this situation, simply discard the remaining small amount of thread.