These soles fit on the Dynamic Walking Foot BLSA-WF. This set contains a 1/4" guide sole, a Stitch in Ditch sole and Long Quilting Guide. These soles have a guide that extends in front of the sole for precise alignment of the fabric. The opening for the needle is not limited to center needle and allows layers to feed evenly with no puckering. The quilt bar will extend in front of the sole and can be used on the left or the right side. (cannot connect to the left when the automatic needle threaders is used.