From The Heroes of Might and Magic III wiki

Artifacts equipped in this slot usually give a bonus to Defense. The artifacts equipped in this slot are:

• Shield of the Dwarven Lords
• Shield of the Yawning Dead
• Buckler of the Gnoll King
• Targ of the Rampaging Ogre
• Shield of the Damned
• Dragon Scale Shield
• Lion's Shield of Courage
• Sentinel's Shield