Chaplet of the Divine Mercy

The Chaplet of the Divine Mercy, also called the Divine Mercy Chaplet, is a Catholic devotion to the Divine Mercy, based on the Christological apparitions of Jesus Christ reported by Faustina Kowalska (1905–1938), known as "the Apostle of Mercy". She was a Polish religious sister of the Congregation of the Sisters of Our Lady of Mercy and was canonized as a Catholic saint in 2000 by Pope John Paul II. Kowalska stated that she received this rosary-based prayer directly from Jesus through visions and conversations, who also made specific promises regarding the recitation of the prayer.

Source: Wikipedia — Chaplet of the Divine Mercy (CC BY-SA 4.0)