Best used with metal items and items containing metal components, the Corrosion Intercept Pouch is a time capsule bag that removes acids from the item stored inside & as they occur over time. We recommend its use with DVD and CD media as well as the usual lapel pins and unknown metal items that folks place inside their time capsules. We offer it in flat in one size - 6x9", opening on the 6" end. The photo shows the 6x9" size. Developed by Lucent Bell Labs. For more sizes see the Zip Lock version.