https://docs.google.com/drawings/d/1PzjaR3kxggVwZiBOBsEVk7UI0lrvdYNr2H2PpakDsWo/edit?usp=sharing
https://docs.google.com/drawings/d/1OlnfjuAFfmP6TvMaPh-Txpsral09VpPZRbzKOjMXgKU/edit?usp=sharing