Twin Weapon Fighting [General, Fighter]

Owing to a great deal of training, you have the ability to wield two identical weapons with ease.
Prerequisite: Dex 17, Two-Weapon Fighting, Weapon Focus
Benefit: You may wield a one-handed weapon in your off-hand at no additional penalty. This weapon must be identical to the one in your primary hand, including any masterwork bonuses (though they may have different magical enhancements). Thus, you may wield a rapier in each hand, but not a longsword and a scimitar or a masterwork flail and a non-masterwork flail.
Normal: Using a one-handed weapon in your off-hand incurs a –2 penalty on all attacks.
Special: A fighter may select Twin Weapon Fighting as one of his fighter bonus feats.