The Velocity Crystal Amulet was a powerful velocity crystal handed out as a prize for winning the Great Atmos Race. Aerrow won the amulet himself, but then shattered it in order to award a piece to each Sky Knight for cooperating in a joint effort to thwart the Dark Ace and the Talons.
The necklace part of the amulet is composed of gold-colored metal plates. The crystal of the necklace is of a royal blue color and a pentagonal shape. An ornament of twin exhaust pipes frames the set crystal.
Although not revealed during the episode, the crystal set in the amulet has the ability to give a vehicle a temporary speed boost. It can be inferred that the crystal was symbolic for racing, and not actually meant to be used.