Cedar Wood's revealer rays are a magical pair of glasses that were gifted to her by her father Pinocchio in "Thronecoming", as part of the tradition of students leaving a present in the Heritage Hall, for their descendants to receive during the Thronecoming events.
Cedar Wood, along with the rest of the 2nd year students, is escorted to the Heritage Hall by Baba Yaga, where a present for each awaits them, with Cedar's being her rays, which she uses to discover some lies, including the major plot twist of the fake Storybook of Legends, which she finds is just a prop through her glasses. She warns everyone about it and sets of the drama. She keeps them on for the rest of the Thronecoming celebrations, but they're of use to a suspicious Briar Beauty, who uses them to discover a hidden secret in her dorm room, the real Storybook of Legends under the floorboards. This causes her to throw it down the Well of Wonder which causes the major disappearance of the book.
The revealer rays are a purple color with golden accents of swirls and leaves around the perfectly round arches. The lenses are the magical element, with a blue hue from the outside. From the inside, that is from the perspective of the one who's using them, the lenses are like a computer and have the power to always reveal the truth behind everything. A little blue pixie inhabits it and will flutter around showing the user graphs and highlights of what's wrong or what's right, revealing secrets.