connect under pressure ends

[jimg]

Was looking at a male push/pull connect under pressure end at the farm store and wondered if theres a corresponding under pressure female end. The particular brand I was looking at had some sort of pressure relief stem in the valve ball. Does this mean the ball doesnt spin? In other words is the stem fixed to the ball or body? Ive never seen one of these before and thought it was sort of interesting. Curious as to what the applications for these are.