I have a Quantum 9240. Very few of the first 9240 were made. It is an excellent machine. It has a better stitch then my Bernina. The bobbins for it are unique to that model. The ones that are listed as will work will not and cause a lot of problems. I had to show the dealer the original bobbin and the new one side by side before he would acknowledge there was a difference between the newer bobbins. They looked alike but the newer one was more domed, only noticeable when side to side with the original. Singer does not make the original bobbins for my machine any more. I have a good supply though.