Waterproof: PANZHU WRAP breathable membrane can reach the EU standard of European Union. The water-proof performance can bear two meters high water column for 24 hours. The water-proof performance is excellent Air tightness: PANZHU WRAP breathable membrane can reach the standard of use Permeability: Water vapour transmission of PANZHU WRAP breathable membrane reaches the international standards of 500 g / ã?¡. 24 h, equivalent to 29.2 of the U.S. perm, Canada's 1665ng/Pa/s/m². Durability: PANZHU WRAP breathable membrane is made of three layers.The upper and lower outer layers are protective layers, which helps the breathable membrane to have good tensile strength and anti-slip, so that it is suitable for sloping roof. Application of PANZHU WRAP breathable membrane