Silver Key

The Silver is a quest item from The Legend of Zelda: Four Swords. Link needs three of these keys in order to access Vaati's Palace.

After defeating the boss of the Sea of Trees, Talus Cave, and Death Mountain, Link will meet a Great Fairy. If he has collected over 1000 Rupees in the stage, the Great Fairy will award him with a Silver Key. The next time Link travels through the stages, he will be able to obtain the Golden Key.