There are as many sizes of bobbin as there are machine (or so it seems at times). Pfaffs are different than Berninas and Singer, and Janome. Some are metal some are plastic, some even screw apart!
Yes, google your machine or get on a site that sells bobbins and type in your machine and the correct one should come up.
Wrong size/style will mess with your tension, stitches and can at times break needles and throw your timing off......