Pass-through glass adapter with a 10mm Female split.  Available in 14mm male to 14mm female, 19mm female to 19mm male or 19mm female to 14mm male.  Most commonly used as a carb to clear your glass piece without having to remove the setup from the bowl, it can also be used in other applications including a splitter adapter or simply to introduce added fresh air.  

*14mm female glass stand sold separately but available here. 

*Like with anything made of glass, please expect some variation in fit and finish.  This is after-all mass produced glass!