The basic modules is also unlocked when reaching E&D S2 for free, while the upgraded versions are unlocked into S&E tree S2 and S4. Here are the modules:
In this screenshot you can see them equipped into a behemoth. As side note, different from economic behemoth, here equipping an engine may be useful depending how far you’re from special nodes you want.
Here you can see that the modules providing science from special nodes all have a beaker, while modules providing other vonus from special nodes will have a galaxy or atom like symbol.
Now the only thing you have to do is park the behemoth over a special node to get the bonus it provides. You also will see the icon over the node and a tolltip similat to an economic behemoth, like in this screenshot:
Keep in mind that the Science produced will be the same regardless the node you’re exploitng, but the discounts you get for researching tech will depend on nodule type. For more info of discounts wyo’ll get from every nodule type, just look at the modules tooltip.