The NEST-Zis a 7.0 mil Moisture Barrier 5-layer bags. With 11,500 PSI tensile strength, 33lb puncture resistance, and >40db EMI attenuation, these bags are great for storage and transportation. Along with those benefits, they are also built for EMP protection of devices should one ever take place. The NEST-Z bags are tested to meet or exceed certain electrical and physical requirements of ANSI/ESD S541 and to be ANSI/ESD S20.20 compliant. Bags are ROHS compliant and lead-free. These bags feature a Ziploc closure system. Used in packaging, transportation, storage, and EMP protection.