The ultimate anti-tarnish protection for storing and shipping jewelry, silver and other precious metals. The same technology used by NASA, the British Royal Mint and Jewelry manufacturers worldwide is available through EURO TOOL for your finest jewelry and silver pieces. Features: Will not harm any metals or gemstones. The inert material will not release corrosive gases like charcoal based products. Temperature and humidity independent. Safe and effective on all non-ferrous metals such as silver, brass, copper and bronze as well as ferrous metals (iron based). Non-toxic, recyclable and environmentally safe. When sealed in bag, items are protected for up to three years. Copper colored backing on bag turns color as an alert to change bag. Available in 4 different sizes Pack of 10.