On some (most?) jazz-style basses the bridge pickup is slightly larger, while on others (like an MIM Fender, as I understand it), both pickups are the same size. A lot of pickup manufacturers sell jazz-style pickup "sets." So say you have a MIM jazz and you want to replace the pickups. You can't buy a "set" because one pickup will be the wrong size, so I guess you have to buy 2 individual bridge or neck pickups? So you buy whatever it is you need to buy to fit your bass. Is the end product any different when you have 2 of the same pickup vs. a "set" ?