I will second that the Aquarium tubing Works well, I have it on my 306w in a treadle stand. does not stretch much, but better than that it is "grippy" and i can run it loose enough to lift my machine slightly to get the bobbin plate off, and it does not slip. I was going to use oxygen tubing ( left over from my father's medical issues) but what I have is "ribbed" on the inside and i could not find a good connector. for the aquarium tubing I just snipped off an inch of tubing then slit the small piece length wise and rolled it up tightly and inserted it inside the two ends of the belt.