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 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. If your Bernina has a single tab across the front of the foot then you need the newer #37 foot #008474.74.00. If you have questions about the feet please give us a call at 800-229-8889 and we will be happy to help you.