This Chaplet comes from an ancient devotion of the Order of Our Lady of Mercy and is based on the Book of Revelation, A great sign appeared in the sky, a woman clothed with the sun, and the moon under her feet, and on her head a crown of twelve stars. (Rev. 12:1) This devotion contains the twelve distinctions of Mary of the Twelve Stars.
The Chaplet consists of three sets of four beads each.