This underlayment :Strengthen the circulation of water vapour, reduce the humidity, improve the living environment.1.Amembrane that can stick PVC or vinyl planks on it,need to stick one side to a concrete slab or plywood and the other side stick the vinyl planks.2.High quality with strong adhesion. The installations of this membrane always be done in the interior of the house and not the exterior.3.Underlayment: water-proof bitumen membrane with two self-adhesive peel-off sides 4. Waterproof bitumen membrane, one side alu foil the other side adhesive peel-offfoil also be available. Thickness: 2mm , 3mm, 4mm. Structure: flatwith high dense Width of the roll: 1m(w) x 18.59m (L) Package: plastic bag, carton box or pallet package.