Moisture barrier bags, also known as foil bags, metallized bags and sometimes provide moisture, corrosion and shielding protection for sensitive components. They are an effective packaging solution to protect against corrosive damage caused by humidity, moisture, oxygen, aromas, grease and other airborne contaminants. These bags are heat sealable and suitable for vacuum packaging. Most contain Polyester (PET) for puncture resistance. The metallic layers provide shielding from Electrostatic Discharge (ESD).