I bought this "doo-hickey" online (somewhere) and I absolutely can't live without it. It's for chain sewing. It has a razor at the top where there is a space on it. So, instead of getting out the scissors or rotary cutter, I use this. I leave it to the left of my sewing machine and when I have done a chain of fabric, I just put the threads (between the fabric pieces) down on it and it cuts it. It separates each piece of fabric you just sewed. I swear it is the most wonderful thing that I have bought in a long time. It makes chain sewing a breeze. It's called "The Cutting Gizmo" and you can get it online at www.thegypsyquilter.com.