In your rocker switches, you offer different sizes of switches for different panel cutouts....

Basically the bigger the switch, the better its electrical performance. Because of the standardization of the market, our rocker switches can be grouped into four standard types according to the panel cutouts:

Of course there are several different cutouts other than the above. They are basically following the patterns above and developed later for customization. However, please note that even two different makers offer their switches with the same cutout does not mean their switches are fully compatible in mounting to your device. Minor difference can still be there and must be checked first by your engineers.