This is a set of two Ball Lock Home Brew Keg Connectors.
This set includes both a gas in and beer out coupler that works with a ball lock Cornelius pepsi keg
The larger hose barb makes it connect to the same size air line that standard draft beer regulators
Gas in has attached the special 1/4" nut that has a 5/16" hose barb
Ball Lock 3/16" Hose Barb Connects to Standard 3/16" Beer Line