What oil can be used in shocks?

What oil can be used in shocks? Is there a specific type? How much oil do they take?
TIA

You really want RC shock oil. It's silicone based and it has stable properties over a wide range of temperatures, unlike other substances people put in it.

They don't take much to fill. A small bottle of oil will last you years. You can get it in a whole range of weights, where higher weight means thicker oil and more damping. 35 is a common middle-of-the-road weight.

@Briguy take a look at the Losi shock oil set, you'll get a set of 20, 25, 30, 35, 40, and 45 wt shock oil for less than $20 and allows you to play around with different weights and find the one you like best.

Is it really as simple as pour out old and put in new push plunger till bubbles stop?
Thanks

@Briguy yeah rebuilding shocks are pretty straight forward, here is a pretty nice video showing how it's done.