This clip on foot fits the clip-on shank adapter and is designed for sewing the 1/4" and 1/8" seam allowances which are common in patchwork piecing.

The three evenly spaced markings (1/4” apart) on its side help you line up your seam allowance when you reach the end and turn, and a narrow groove under the flat sole serves as a thread channel for smoother piecing.