This product is used to relieve pressure when transferring , filtering, fermenting, or priming beer. The PSI range on the gauge is 0-15 PSI.
When filtering: This connects to the gas fitting on the keg you are filtering into and has adjustable relief valve for letting pressure off as the keg fills up plus it allows you to read the pressure in the receiving keg.
Notes: Does NOT include the gas fitting (add as an option).
You need to wind/unwind the end of the valve to adjust the pressure. It sometimes comes threaded all the way on from the manufacturer occasionally. Wrap a towel around the end piece(about 1/4 in) and clamp down on it while twisting the wrench fitting on the bottom(closest end to the Gas In QD) to loosen it. Then finger tighten or loosen to desired pressure.