I rushed threw this video and I left out a lot of information and some of the details where not on point. However if your interested to learn more, I have included this link.

Everything you could ever want to know about this compressor listed below.
https://www.shareddocs.com/hvac/docs/...

Edit:
there are 2 types of unloaders, hot gas bypass and suction cut off.
I said in the video it was hot gas bypass but it was actually a suction cut off.
here is a link http://bcr.us.com/technical-data/capa...