Somewhere on line I found these jaws thingies. There were 12 or so of them in a set and they clamp the middle of your quilt sandwich to the lower backing roller. The bottom part of the sandwich falls between this bottom roller and the quilt top roller and are snuggly held in place. You use it when you have to put a quilt back on the frame for repair work, etc. Can any one tell me where I saw this.