This item is a (4) Way Barbed Coupling used to couple 3/8" ID hose together.
3/8 Inch Barb X 3/8 Inch Barb through and a tee Barb Coupling 3/8" barb and 3/8" barb...
This part is used on pump bleeder systems many time where the bleeders are attached together to one outlet..
For other 3/8" Air Line Related parts click this Link: https://spaguyparts.com/search.php?search_query=3%2F8%22+
