I bought one. You sew your binding to the back and then you use this foot to sew your binding to the front. It was a hassle for me to get use to at first but it really worked. I bought it with the zip bind system, which was a pain in the neck by the way. But if you used this foot and worked slowly and carefully, it worked perfectly. But I became impatient. Maybe I need to get that back out and try it again on my quilts I need to bind. I'm planning on machine binding them to the front anyway. So, to tell you, it really works. It takes some getting use to is all. And some patience!