What model Viking do you have? I have two old Vikings, a model 21 and a 21A. They are both low shank machines and take standard low shank feet. I purchased a generic low shank walking foot and it works fine on my machines. There is a Yahoo! group for vintage Viking owners where you can get lots of information on these wonderful machines as well. This is where I go whenever I have a question or need assistance. I love my little green machines :)