Dura-Pex vs copper pipe

[_RaT_]

_RaT_
Did by any chance you see if the PEX tubing went into the Tankless hot water heater? I just had one of these installed, and they used coppper coming out of the tankless unit to mate to the plastic cpvc in the rest of the house.

Thanks,
Scot

They used copper out of the tank and converted to PEX once through the metal cabinet.