My main complaint is that the gauge fouls the filter housing; this is a basic design failure. The gauge does seal very easily with ptfe. I initially put the gauge on nice and straight and it did not leak. I had to remove the filter housing as the auto water outlet was leaking; this caused the gauge to rotate, the gauge still isn't leaking but is a bit crooked and I'm not going to loosen it to make it level. The water outlet was leaking as the was a little piece of ptfe trapped in it (not my doing). I had bought a male/female extension to set the gauge out from the filter body but rather than measuring the gauge threads myself, I trusted the instructions. The instructions are wrong, they state the gauge ports are 1/4" NPT but they appear to be 1/8". I haven't bought another NPT extension, I've just decided it'll do. My system looses some air but it will have to do. I don't think this was good value, if I had it to do over I would get a cheaper silverline one on the basis that it couldn't be any worse put together or designed.