Review on Rhinox Stainless Steel Needle Valve for Solenoid Fish Tanks - Accurate CO2 Regulation and CO2 Adjustment with Rhinox C02 Diffuser Set by Emma Santos

Useless for me. Whether closed or open, it lets through the same amount of CO2. Doesn't even block the flow. Edit 2/16: I'll admit that I seem to have installed incorrectly. It seems that "Input" is the opposite input to the control knob and "Output" is the other. I'm changing this to 4 stars due to the lack of instructions. Edit 10./16. February: Not a big range. I have to close it hard to actually stop the flow of gas, and at the minimum opening it starts sending too much. Is it the pressure in my system or something else (DIY system)