I found one of these...
https://www.pinterest.com/pin/331225747572808734/ at a thrift store today ($5.00), but I think mine is for low shank because the part that goes on the needle bar is different. Is anyone familiar w/this attachment? Does it need those little round things that go on the sides? There are none in the box, but I got the little things that are shown in the picture. Sorry I don't know what the parts are called!
So, if anyone can tell me more about this, or point me somewhere I can read about it I would be thankful.