In the Orthodox liturgical tradition, the omophorion is one of the bishop's vestments and the symbol of his spiritual and ecclesiastical authority. Originally of wool, it is a band of brocade decorated with crosses and is worn about the neck and around the shoulders [1] (http://www.svots.edu/Press-Releases/2003-0914-nikoncross/liturgy/pages/liturgy28_jpg.htm). By symbolizing the lost sheep that is found and carried on the Good Shepherd's shoulders, it signifies the bishop's pastoral role as the icon of Christ.
When the rubrics call for the omophorion to be removed and replaced frequently, the standard great omophorion is replaced for the sake of convenience with the small omophorion, a shorter band worn after the manner of an epitrachelion. In some places, when several bishops concelebrate, it is now the custom for the chief celebrant to use the great omophorion when called for, and the other bishops to wear the small omophorion throughout [2] (http://www.svots.edu/Events/Orthodox-Education-Day/2004/pages/DSC_0094_jpg.htm).
Clergy and ecclesiastical institutions subject to a bishop's authority are often said to be "under his omophorion".
The equivalent vestment in Western Christian usage is the pallium, whose use is subject to different rubrics and restrictions.
In Oriental Orthodoxy the omophorion takes a number of different forms. The Armenian Orthodoxemip'oron is similar to the Byzantine great omophorion. The Syriac Orthodoxbaţrašil or uroro rabbo ('great stole') is a straight strip of embroidered material, about 20 cm wide, with a head-hole midway along it, that hangs down a bishop's chest and back. Coptic bishops used to wear the omophorion wrapped around their heads like a turban: this was called a ballin.
Pontifical vestments are the liturgical head-covering, excepting in the Armenian Rite where the priest also wears such a covering for the head, the sakkos, the omophorion, the epigonation, and the epimanikia.
It is even possible, though not demonstrated, that, as early as the close of the pre-Constantinian period, liturgical insignia came into use among the bishops and deacons, as the orarion, or stole, and the omophorion or pallium.
The omophorion and orarion were the first to receive symbolical interpretation, which was given by Isidore of Pelusium (died about 440); the earliest symbolism of the entire priestly dress of the Greek Rite is found in the Historia ekklneiastike, probably of the eighth century.
Small Omophorion: Worn after the Gospel reading until the conclusion of the Divine Liturgy because from that time on he is a simple celebrant and servant of the Lord.
The Omophorion, both Great and Small, are usually decorated with the figure of Christ or that of a lamb and are symbolic of the stray sheep that Christ, the 'good shepherd,' carried on his shoulders.
Pectoral Cross: A cross of precious metal and jewels lays over the Omophorion and is worn as a reminder that the Bishop bears his cross and upholds the commandments of Scripture and faithfully fulfills the holy and saving words of Jesus Christ.