I currently have an oba system with an Extreme Aire 12v compressor and a 2.5 gallon tank. The compressor has 1/4" threads, but a 3/8" internal diameter opening. I used 1/4" fittings and 1/4" ID air lines to connect the compressor, air manifold, tank, etc. I've read other posts where people did the same thing, but then said they wished that they had used 3/8" ID fittings and lines. I can see the benefit of that from the tank to the air outlet, since there're no restriction points. From the compressor to the air maifold and tank though I'm not so sure it's beneficial because of the check valve. It seems like since the check valve has the smallest opening in the entire system, even smaller then the 1/4" fittings, and is the first piece of hardware after the compressor, I don't see the benefit of using 3/8" ID fittings and lines after that choke point. Am I wrong? Would I get more airflow from the compressor to the tank using 3/8" ID fittings and lines even though the check valve has a smaller opening?