Power Bracelet

The Power Bracelet(s) are an item that increases Link’s strength to almost super human ability. They are more common in the 2D Zelda games, but have also made appearances in The Wind Waker, and a similar type of bracelet (the Silver Gauntlets) could be found in Ocarina of Time. Another similar item appears in A Link to the Past; the Power Glove and it's upgraded form, the Titan's Mitt, have the same effect as the Power Bracelets.

It can be assumed that the Power Bracelets have been scraped for most 3D Zelda games because of the use of bombs on bigger rocks, and the unrealism of needing a bracelet to lift smaller rocks. Although they are mostly called Power Bracelets, there are very rarely two of them, the only such occasions having been in The Wind Waker & The Minish Cap

The Legend of Zelda
With the Power Bracelet, Link is able to lift heavy objects such as rocks. The bracelet is hidden underneath an Armos Statue somewhere in Hyrule.

Link's Awakening
The Power Bracelet is found deep with the Bottle Grotto, and is protected by two Boos. It is required to destroy the main boss of the dungeon, as well as continuing in the adventure.

Later, in the Face Shrine, a Level 2 upgrade is awarded which enables Link to lift heavy items.

Oracle of Ages & Oracle of Seasons

 * Oracle of Ages (in Spirit's Grave)
 * Oracle of Seasons (in Snake's Remains Dungeon)

Four Swords Adventures

 * Four Swords Adventures (various levels)

The Wind Waker
The Wind Waker (in Fire Mountain).

The Minish Cap

 * The Minish Cap (in the Town Fountain)