What is the difference between the XPRESS and the Promax Polyflo culvert pipes?

Promax Polyflo pipes are single wall corrugated pipes.

XPRESS are double walled, with a smooth inner and corrugated outer. 

Promax Polyflo pipes are available in a range of diameters ain 2.7m and 5.2m lengths.

XPRESS culverts are available in a range of diameters and 6m lengths.

For full specifications on the pipes see the product detail pages.