Help me identify this pipe for Flow Meter Installation

[though]

Going to install a Flow Meter. The Backflow Preventer shows 3/4". Do I just follow the 3/4" PEX install guide?

Also, is it ok to “substitute” the 6" transition pipe for copper instead of pex?

Thanks fellas!

[spscoutenPhD]

That looks like a type of PEX pipe but with insulation. I take it that you are in an area of the country with extremely cold weather.

Copper is a good choice for your connection and transition.

[though]

I cut out a section and took it to my local plumbing shop. They identified it as Viega Fostapex. They gave me a solution with fittings to get the flow meter installed and here it is!