From Pathfinder Lost Omens Character Guide, which isn't enabled.

Fortifying Pebble

ITEM 4

UNCOMMON CONSUMABLE MAGICAL TALISMAN

Price 13 gp

Usage affixed to armor shield or weapon

Bulk —

Category talisman

Usage affixed to armor, shield, or weapon

Activate envision

Trigger The affixed object would take damage

This small pebble is strangely dense and surprisingly durable, affixed to an object by a sturdy steel chain. When you activate the pebble, the affixed object takes 10 less damage.

Pathfinder Lost Omens Character GuideOGL