Hydraulic Shock? Snubber?

It's a "snubber". It's used to provide lateral support, to prevent fast movement, but freely allows slow movement due to thermal expansion/contraction. Scroll half way down the linked page to "snubber".

References:

http://www.whatispiping.com/dynamic-restraints

Reason:
Thank you for the opinion, I see how it can be a snubber but can you please be more specific in what machine this one will fit, thank you

The snubber doesn't fit a specific machine. They're used in large scale piping systems, where a mechanical engineer specifies the type and routing of pipes. He/she then specifies the proper supports needed for the piping. A snubber is chosen to meet the needed requirements of that specific piping arrangement.

References:

https://www.lisega.de/zh-hans/services-zh-hans/%E7%8E%B0%E5%9C%BA%E6%9C%8D%E5...

http://www.pipehangers.in/old_files/restraints.htm

Reason:
Thank you for the answer, but I am hoping to find an exact match for this item that looks the same, at least in size. This will not count against your score.