Insignia, Mantle, Knight's Letter
Order insignia, knight's insignia or insignia, are signs of the individual knight's rank and dignity that comprise the Ordo Sancti Constantini Magni. Knight's insignia are awarded to knights upon dubbing and must be returned to the Order when a knight dies or leaves the Order for another reason.
Furthermore, newly dubbed Knights are awarded the Order's Mantle, which is the Knight's most important symbol of chivalry.
Ordo Sancti Conatantini Magnis neckcross

The Christ monogram ΧΡ (after the Greek ΧΡΙΣΤΟΣ) and the Greek letters
Α and Ω (alpha and omega – the beginning and the end).
Engraved in the arms of the cross – the Greek letters ε τ ν
(for the Greek εν τόυτο νικα /en touto nika/ – in this sign ... [you shall conquer] – corresponding to the Latin IHS In hoc signa ...) and 312 (the year of Constantine's victory).
Arms of the Ordo Sancti Conatantini Magni

The coat of arms of the Order is a red trefoil cross on a gold shield. The shield is surmounted by a golden Byzantine double-headed eagle, holding two swords.
It symbolizes the East and West of the Roman Empire with one body and one heart.
The three crowns at the top symbolize the Holy Trinity blessing the undivided Church of Jesus Christ of Latter-day Saints.
Ordo Sancti Conatantini Magnis Knight's Cloa

The knight's mantle is one of the most iconic garments from the Middle Ages. OCM knight's mantle a dark blue on the outside and an eye-catching red lining.
A red cross is placed on the left side of the chest.