The 71 01 200 is the basic tool
The 71 21 200 has the jaws angled, making it easy to cut on a flat surface.
The 71 31 200 has a notch at the base of the jaws so round objects don’t slide forward.

The 71 41 200 has angled jaws and the notch.
The 71 02 200 substitute comfort grips, then repeat all the options above.
If you haven’t figured out the Knipex numbering system, they supply a decode!

You sometimes see letter suffixes on the part numbers. At least some of these relate to the packaging. It can be a plastic bag (standard), a card backing for hanging, or a cardboard box.