Improved Sunder [General]
Prerequisites: Str 13, Power Attack.
Benefit: When you strike at an object held or carried by an opponent (such as a weapon or shield), you do not provoke an attack of opportunity.
You also gain a +4 bonus on any attack roll made to attack an object held or carried by another character.
Normal: Without this feat, you provoke an attack of opportunity when you strike at an object held or carried by another character.
Special: A fighter may select Improved Sunder as one of his fighter bonus feats.
Source: SRD 3.5 Feats