BIG FOOT is a giant darning foot designed to give you more control when free-motion machine quilting. Lower your feed dogs when using BIG FOOT. Cover with an index card or business card if you cannot lower feed dogs (e.g. Elna: DO NOT COVER with feed dog plate.)
The "finger" at the top of the foot should rest on the needle screw.
The large clear foot makes it easier to follow continuous line quilting patterns because of excellent visibility.
You have more contact with the fabric sandwich which will give you better stitch control. Sew at a steady, medium speed.
From the center of the unique mushroom-shaped slot it is approximately 1/4" to either end of the slot. This provides a guide for echo quilting.
BIG FOOT will fit any machine that can use generic low-shank feet. (Bernina requires the low shank BIG FOOT and the Bernina long-shank adaptor part #001947 7000.)