Mask of Elemental Energy

The Kanohi of Elemental Energy was a Great Mask that instantly recharged a Toa's Elemental Energy. This mask was featured in the 2003 video game, Bionicle: The Game. Although the game was non-canon, the mask has been confirmed to be part of official canon.

In Bionicle: The Game
The Kanohi of Elemental Energy was a healing item that, when used, restored all of a Toa's Elemental Energy. Its powers were activated instantly upon grabbing the mask, and each could only be used once.

The masks were scattered all over the levels, some right in plain sight, and others hidden well. In the trailer, it is seen dug up by Onua Nuva.

Trivia

 * The mask also appeared in BIONICLE Heroes, though it was only to be viewed in the Trophy Room.