Taprite regulators connect to your CO2 Tanks, and reduce the tank pressure to a suitable pressure for kegging and serving your favorite carbonated beverage.
CGA-320 Connection to cylinder.
Secondary regulator is to add a 2nd, or 3rd or... pressure AFTER a high pressure regulator. Set the primary regulator to the highest desired pressure (Max 50 PSI), the secondary will drop to a pressure below that. Secondary regulator 3/8" barb in/thru, 5/16" barb shut-off.