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From Pathfinder Impossible Magic, which isn't enabled.

Spellshock Shield

ITEM 11
ELECTRICITYMAGICAL
Price 1300 gp
Bulk 1
AC Bonus +2
Hardness 7
HP 28
BT 14

This moderate reinforcing steel shield (Hardness 10, HP 92, BT 46) is inlaid with jagged crystalline veins that hum with stored energy.

Activate—Crackling Arc (concentrate, electricity, manipulate)
Frequency once per day
Trigger You succeed at a Reflex saving throw against a magical effect while the spellshock shield is raised
Effect A jagged bolt of unstable energy lashes out at a creature within 120 feet, dealing 4d12 electricity damage (DC 28 basic Reflex save).
Pathfinder Impossible MagicORC