These anti-tarnish tabs work like magic. Place them in enclosed spaces with jewelry and they will fight off tarnish and discoloration on silver, gold, copper, bronze, brass, & pewters. You can use these to care for jewelry, instruments, flatware, or trophies. These have no fumes or residue on the metals being protected. A single tab can protect a space of approximately 30sq inches (a 3inch box). Sold in packs of 10. Anti-tarnish tabs have an approximate shelf life of 2-years once out of their sealed bag.