A.P.I. Firearm Storage Bags work by emitting VCI molecules that are drawn and instantly cling to any metal surface placed inside the bag. This creates a buffer between harmful corrosion-causing elements and the metal surfaces in the A.P.I. Firearm Storage Bag. This buffer prevents corrosion from forming keeping your firearm as clean as the day it was first stored. Each time the storage bag is opened some of the VCI molecules escape from the bag however, more VCI molecules are then emitted from the inner material of the storage bag to replace the lost molecules. Firearms that are removed from the A.P.I. Firearm Storage Bag several times throughout the year will still last at least five years and infrequent removal will help extend the life of the storage bag far beyond five years.