It's glass about 7" long. There's a screen in the glass where the "barrel" meets the taper and that aluminum cap unscrews. It has a screen in it too. That slot in the aluminum is to attach it to something. 
Guess what this is.
It's glass about 7" long. There's a screen in the glass where the "barrel" meets the taper and that aluminum cap unscrews. It has a screen in it too. That slot in the aluminum is to attach it to something.