The Bernina #37 Patchwork Foot is a 1/4″ wide on the outside of both sides of the foot allowing you to make precise 1/4″ seams when quilting. On the inside of each side is 1/8″ wide. This is the older style foot that has 2 prongs on the top for connecting to the older Bernina machines. This foot fits older Bernina machine models 530 to 1630.