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From Pathfinder Treasure Vault (Remastered), which isn't enabled.

Reflecting Shard

ITEM 13
Price 500 gp
Usage affixed to a shield
Bulk —
Category talisman

Activate (concentrate)
Trigger You are targeted by a spell of 5th rank or lower
Requirements You're a master in Athletics, and you have the affixed shield raised.

This mirrored metal fragment is bolted or welded to the face of the affixed shield. When you Activate it, you attempt to reflect the triggering spell back at its caster with Spell Riposte, using your Athletics modifier for the counteract check. The talisman's counteract rank is 7th.

Pathfinder Treasure Vault (Remastered)ORC