Questions about flush mount valve stems

I’m thinking about getting flush mount valve stems for the wheels I just bought. How well does the filling adapter work? Does it fit well in the stem and is filling just as easy as normal valve stems? Are there any cons with these? Thanks.

Never mind, I came across an animation of how they work and it answered my questions. Here’s the link for anyone that’s interested:

http://www.cbperformance.com/catalog.asp?ProductID=1213