Gold rings (bangle)

The Inhibitor Rings are golden rings worn on the wrists of Shadow the Hedgehog. Although never stated, they were presumably created by Professor Gerald Robotnik or another scientist aboard the Space Colony ARK. When Shadow removes them in the different canons, he receives an increase in power. First appearing in Sonic X, they were not named "Inhibitor Rings" until adapted by Archie's Sonic the Hedgehog comics.

Sonic X
The first removal of Shadow's rings appeared in Episode 38, where Super Shadow removed them to boost his Chaos Control. Although called "limiters" in the Japanese version of Episode 73, there is little explanation as to how they work: it may be an inversion of how the Sonic X version of Sonic would get a similar boost from gaining a Ring and they were only removed in close proximity to a Chaos Emerald or a fake Emerald. Shadow removed them for a boost several times throughout the series. He quickly loses energy and collapses after the boost of power or when he is without them for any period of time in battle. The limiter rings are connected to the red tongues on the black cuffs of Shadow's gloves, the red tongues disappear when the limiters are removed.

Archie's Sonic the Hedgehog comics
Adapted from the Sonic X version, the Inhibitor Rings are both named and more throughly explained in the Archie comics: they used by Shadow to limit the amount of power he uses during combat and other situations. When he takes them off and uses his Chaos powers he becomes thoroughly drained of energy. He was first seen using this method of power enhancement during his battle against the second Enerjak. This caused his Chaos powers to increase dramatically and for a time match Enerjak's, nearly tearing the whole city of New Mobotropolis apart in the process. He later used them again when on a mission in the ruins of New Megaopolis to destroy Dr. Eggman's Doom Laser. In this mission, Shadow took off his rings to divert the shot of the laser using Chaos Control and his plan worked successfully, though he nearly fell off the observatory the Doom Laser was housed in. (StH: #182 SU: #2).

Sonic Games
The games eventually adapted the concept as well in Sonic the Hedgehog (2006). When Mephiles the Dark had stolen Shadow's Emerald and replicated himself into an army, Shadow removed his rings to boost his power to attack. Like in Sonic X, they are not named and there is little explanation; and the ability has thus far only been used once.