Brother Metal bobbins, 5pk - SA163

These Brother SA163 Metal Bobbins for ULT Series are slightly heavier so they increase the bobbin tension slightly and help decrease the chance of bobbin thread showing on the right side of the embroidery. Genuine Brother® Accessory. Brother SA163 Metal Bobbins for ULT Series sewing and embroidery machines that use the plastic SA155 bobbin. 

They also sit securely because there is a magnet in the bobbin case. For use with: ULT-2003D, ULT-2002D, ULT-2001, PQ1300, PQ1500, PC8500