Thank you for viewing. This is a Janome Feed Jaws Walking Foot. It feeds fabric while gripping it with upper and lower teeth, so it prevents slippage and wrinkles when used on materials like thin knits, vinyl leather, and leather. This was included with a Janome sewing machine. It's for standard horizontal rotary hook household sewing machines (low shank specification). It cannot be used on embroidery machines like the Secio or industrial sewing machines because the presser foot holder position is high (high shank). I don't know the specific machine models it fits, so please check. Just in case, I tested it on my Janome sewing machine (Memory Craft 5100) and confirmed it works without any problems (see image). I measured it, and the distance from the bottom of the basic presser foot to the center of the holder mounting hole was 16mm. Also, it cannot be used on machines other than Janome. Please be aware. If you have any questions, please feel free to contact me. Thank you.