These are not options provided by the program. They are options provided by the printer. There are only a couple of options that are actually provided by the program itself. For example, if you are printing a card, the options that are provided by the program are:
Hallmark Paper Stock 8.5 x 11 in.
Hallmark Traditional Size
Avery 3265 Half-Fold
Avery 3266 Quarter-Fold
Avery 3254 Print to Edge
Avery 3273 Print to Edge
Anything listed after that is from your printer. When you go to the print screen, the program queries the printer's driver to see what paper size options it will provide. It then lists those options as part of the list after the options from the program. If you want confirmation of that, you can go into the Printing Preferences for your printer and look at the list of paper sizes that are shown in there.
So, basically, if you want to know what those dimensions are, you will need to consult the documentation that came with their printer. We will not have that information here, as we do not know what shows on the list in your program, and it is likely that we do not have the same options.
Also, this means that different printers will show different options to print to. This is why when printing to one printer it may have options that another printer does not display and vice-versa.