This pendant is for a rosary type necklace. It has connectors at either side of the top, and one at the bottom center. This way you can add the bottom half of the rosary beads and not have to worry about how to add them.
The pendant says (some words I can’t read or understand), “Pray for Us”, and some St.’s name on the front, and then some weird lettering on the back. Never seen lettering like that before, so I can’t say what it says or means.