Dazing Coil
Item 14ConsumableEnchantmentMagicalTalismanSource Core Rulebook pg. 566 2.0Price 900 gp
Usage affixed to a weapon
Activate 
envision;
Trigger You deal damage to a flat-footed creature with the affixed weapon
This knot of copper wire reshapes itself in a new pattern every time its affixed weapon deals damage. When you activate the coil, the damaged creature must succeed at a DC 31 Will save or be stunned 1. If it critically fails, it instead becomes stunned 2.