As the headline says, the knob is not rigidly attached to the tank-side threaded adapter. I guess this is in case someone wants to use a wrench instead of the plastic knob (why would you though?). Either way, I feel like the plastic knob should have at least snapped into position so it didn't easily slip off the end. I can't help but feel like I'm going to loose the knob within a year...
The knob is not rigidly attached to the tank threaded adapter.