How do I rotate a mesh back and fourth?

Hello guys,

Very new to blueprints, been watching tutorials on timeline for hours, I cant find anything that shows how you can rotate something lets day 30 degrees, and then back 30 degrees on loop, like a desk fan rotating?

I know of the rotate component but that does not left you reverse the rotation, please someone put me out of this misery ha, thank you!

Hm, the most compact I can think of:

Image from Gyazo

Just a super quick example, this can be made much more fan-like, of course!