The Blue Generic Ruler Foot Large fits high shank sewing machines. Attach the Blue Generic Ruler Foot (GRF) to your machine by removing the screw holding your foot on the shank. Adjust by placing a quilt sandwich under the foot and check that the fabric moves freely under the foot, then tighten the screw firmly. Position the needle in the center. You cannot lower the needle when the foot is raised. The Blue Generic Ruler Foot is designed to work with 5mm rulers that are thin enough to pass behind the GRF, so you can make your figures with the ruler. Use ruler work for your decorative quilting, straight lines and elegant soft curves.