Conversely, there is nothing wrong with the "cheap knock off" fittings. They have worked fine for me with filters, compressor, adapters, etc. I have a 98 cf JB tank, whip and adapter and the fitting shoulder clearances on some of the fittings are too close for the standard economical fittings, though all these seem to work fine with each other.. You will have to decide if you need to switch out to the cheaper fittings, as needed, or switch out to JB's "premium" fittings @ 3 times the cost to accomplish compatibility.