What Tier Research Are Pumpjacks?

Hye guys, I know quarries are tier 2 for research but what about pumpjacks? It’s either 2 or 3

Thanks

This link hasn’t been updated for devblog 73, so a couple things might be inaccurate.

They can be found with pages, though it took me a week to get a bp for one.

So around 40~ish pages.