The Saint Benedict medal is engraved with the initials of a very old prayer against the temptations of the devil.
PAX = peace
Letters inside circles: Crux Sancti Patris Benedicti - Cross of the holy father Benedict
Vertical line on the cross: Crux Sacra Sit Mihi Lux - The holy Cross be my light
Horizontal line: Non Draco Sit Mihi Dux - Let not the Dragon be my guide
Around the medal, right side: Vade Retro Satana Nunquam Suade Mihi Vana - Get away Satan Never tempt me with your vanities
Around the medal, left side: Sunt Mala Quae Libas Ipse Venena Bibas - What you offer me is evil Drink the poison yourself