On the day of release, the spirit shields were listed in the Grand Exchange, but could not be traded and their image could only be seen in-game.
Players originally needed 35 Prayer to wield a spirit shield, although 55 Prayer is required to complete the quest.
The Spirit shield is much like the Godsword blade. Both items can be modified with 4 different enhancers that are dropped by high level bosses. Spirit shields use sigils while godswords use hilts. Please note, however, that unlike the godsword, the spirit shield cannot be altered once a sigil is attached.
The Spirit shield is worn by Meranek Thanatos, the ghost that helps you slay the Spirit Beast and is actually the same shield - Meranek gives it to the player upon completion of Summer's end.
While a player wearing a Spirit shield is hit by an opponent's attack, a unique sound is played, it is similar to the sound of getting hit when you are wielding any shield from the Elemental Workshop quests.