Easy to Disassemble and Assemble: it can be moved and adjusted, clip it on when it is in use, and take it off when it is not in use, which is very flexible. Function: The opening on the head of the auxiliary device is specially used to clamp the inner seam for fixing. Material: Made of high quality stainless steel material, very sturdy and durable. Portable: Small, durable, easy to use, and can even come and go inside the sleeve. French seam seam on a garment,etc with the raw edges turned and sewn under. Simple to install and easy to use, it is an essential part of a sewing machine.