5-layer multilayer embossed (nylon and polyethylene), 105 micron thickness which makes the bag soft and less fragile. The differentiated layers of polyethylene make it more resistant to moisture penetration, the nylon layer protects against the ingress of air. Certified for boiling up to 100 ° C. Certifications: 1935/2004 CE - 1895/2205 CE - 10/2011 CE - DM21 / 03/1973 - DPR 777/82