What exactly is this? I know what an ash catcher is. What does the term Inline refer to? As I understand it, a diffusor is the bottom part of the downstem that contains a number of small holes which creates for a smoother ripskie. I currently have one of these "diffusor" style downstems in my HVY water pipe. Do they make ash-catchers nowadays that not only performs "catching the ash" but also has a built in difussor? I'm kinda confused, if someone could post some pics it would be helpful. I ask because i'm getting my Vriptech heat wand tomorrow and feel like I need to add one of these devices to my HVY piece to make the rip THAT much smoother. That, or if you have any recommendations as to what kind of glass I can add to my current setup to really put it over the top. 
Thanks!
Thanks!