Apollo 3/4 in. Brass PEX-A Expansion Barb Coupling (10-Pack). 

Model #EPXC3410PK

Pro pack includes 10 fittings
Larger internal diameter of Apollo expansion PEX fittings results in a 25% greater flow rate within the system
Constructed of lead free dezincification resistant (DZR) brass for superior reliability and strength
A cold-expansion tool (sold separately) is required for installation
Meets or exceeds ASTM F1960 standard
Meets UPC, IPC and cUPC standard
Must secured in place using Apollo expansion PEX sleeves or other PEX-A expansion sleeves/rings
NSF Listed
Barb x barb connection for PEX-A plumbing systems
Go/no-go gauges are never required
To ensure secure connections every time, fittings cannot be dry fit
Rated to 200F and 200 psi
Item is not compatible with PEXb pipe, crimp-style (ASTM 1807) or pinch clamp (ASTM F2098) piping systems