This beautiful holy card portrays St. Gabriel the Archangel whose feast day is September 29.
The prayer on the back reads:
O Blessed archangel Gabriel, we beseech thee to intercede for us at the throne of Divine Mercy in our present necessities, that, as you did announce to Mary the mystery of the Incarnation, so through your prayers and patronage in heaven we may obtain the benefits of the same, and sing the praise of God forever.