Tuplex is made out of two layers of solid polyethylene with flexible polystyrene granules between the layers and recommended by Kahrs, but is suitable to support any engineered wooden floor floating system.
It comes with a built in Damp Proof Membrane which is a requirement for concrete sub-floors.
Suitable for all areas of the home, including ground floor, basements, and 1st floor environments. This product is not designed to be used as an acoustic underlay.