What is this cylinder like part?

Question

I found a pair of these among some parts I bought. It looks like some sort of cylinder, which could hold an axle for a piston.

Is that correct, and how would I use it then?

Answer 1

This is one half of a "hydraulic" cylinder used like in the bucket of 7685-1: Dozer.

This element is Fric. Element, Cylinder and used often used in combination with Stick 6M W/Flange

Answer 2

This, at least as far as my experience goes, is used simply to create extra friction in joints; to make something poseable yet stiff and able to hold its position. Sorry no pic, but a good example is the 8996 Scorpio XV1, a walking machine that uses these to keep the legs stationary unless you actually want to move them.