This looks like the first video test of regulators used for HPA powered airsoft guns courtesy of Airsoftjunkiez. Find out which you think can do best for your airsoft rifle... "Airsoftjunkiez MK18 custom build shooting in full auto was used to test the refresh rate of 4 regulators. SLP ARX-20, Redline SFR, Wolverine Storm & Ninja LPR."