I believe it is the carb - if so... what does that mean lol?

**Edit** I guess as far as the knob goes - it looks like this one : http://777bongs.com/images/purple-bong.jpg
Mine, is a straight bong though, I doubt that makes a difference for the knob.

Thanks again
Filiab Reviewed by Filiab on . My First Piece!!! (Pics soon) So I went today on a whim, and bought my first piece, a lame piece, but a first none the less. I'm pretty broke, but been wanting a bong for ages - bought myself a $20 transperant purple bong. Not too tall, kinda small, but pretty good for my "nosy" parents. But now for two questions (never used a bong); there's a black rubbery knob on the back, what is that ? And when I'm using it, I've seen people take out the stem/bowl when the inhale, for my acrylic is it the same? Thanks a lot Rating: 5