Your studies have helped you develop methods to overcome spell resistance.
Benefit: When you cast a piercing spell against a target with spell resistance, it treats the spell resistance of the target as 5 lower than its actual SR. A piercing spell uses up a spell slot one level higher than the spell's actual level.
出典：Pathfinder Society Field Guide
Aura moderate abjuration;
CL 9th Slot none; Price 500 gp; Weight ―
Derived from the patient distillation of
rare magical reagents, a pinch of this fine white powder
can be added to the casting of any spell as an additional
material component to give the spellcaster a +5 bonus on
caster level checks made to overcome spell resistance.
Craft Wondrous Item, Spell Penetration; Cost 250gp