The medal of the Immaculate Conception, also known as the Miraculous Medal, was revealed by Mary herself in a vision to St. Catherine Laboure on July 18, 1830. It bears the image of Our Lady, along with the words, "O Mary, conceived without sin, pray for us who recourse to Thee," surrounding it. The back of each Miraculous medal features an "M", surmounted by a cross, with the hearts of Jesus & Mary.