The Magic Bobbin Washer eliminates backlash and bird's nests on the underside of free-motion quilting, thread painting, or embroidery when changing directions at high speed. Easy to use, just drop a bobbin washer into the bobbin case, replace the bobbin, and insert into the machine. The super slippery Teflon is tough and durable, creating a long-lasting tool. With less stopping and starting, the Magic Bobbin Washer saves time and headaches! Little Genie Magic Bobbin Washers, eliminates backlash and bird's nests in the bobbin case. 12 bobbin washers come in a pack. Made of Teflon. Fits bobbin cases in all long-arm and home machines.