A Green Lantern Ring, also known as a Power Ring, is a piece of jewelry worn by a Green Lantern. It grants the wearer incredible and incomprehensible powers and abilities by harnessing willpower. They are considered by some to be the most powerful weapons in the known universe. Depending on the skill and willpower of the wearer, it can do almost anything. It needs to be periodically recharged by being placed inside a green lantern battery while reciting the green lantern oath.