A strand of 100 wooden beads, the Jesus Beads are a devotional rosary honoring the name of Jesus and imploring the mercy of God.
A printed card includes a brief explanation and history: Jesus Beads originated in the tradition of the Orthodox and Eastern Catholic Churches. Called a chotki, this metal linked strand has 100 dark brown wood beads and a Byzantine icon-style crucifix.
The chotki is traditionally used as a silent "breath prayer", with "Lord Jesus Christ, Son of the Living God" prayed on inhalation and "have mercy on me, a sinner" prayed on exhalation. This is known as the Jesus Prayer, or the Prayer of the Heart, which invokes the Holy Name of Jesus and implores His divine mercy.
(You can read about the "Jesus Prayer" in the Catechism of the Catholic Church, paragraphs 2665-2669.)