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

Reverberating Stone

ITEM 11

CONSUMABLE MAGICAL TALISMAN

Price 275 gp

Usage affixed to a shield

Bulk —

Category talisman

Activate (concentrate)

Trigger You use the affixed shield to Shield Block a melee attack

Requirements You're a master in Athletics, and you have the affixed shield raised.

This heavy metal emblem is mounted on the face of the affixed shield and has a dull gray gemstone embedded at its center. When you Activate the talisman, the gem shatters, releasing a powerful shockwave in a 15-foot cone that must include the enemy who struck the triggering blow, if possible. Each creature in the cone takes 2d6 sonic with a DC 28 basic Fortitude. Any creature that fails its save is pushed 5 feet away from you (or 10 feet on a critical failure).

Pathfinder Treasure Vault (Remastered)ORC