You can make a quick attack with your off-hand weapon.
Prerequisite: Dexterity 17, Two-Weapon Fighting, Improved Two-Weapon Fighting, base attack bonus +6.
Benefit: Whenever you make a single successful melee attack with your primary hand, you may attempt an off-hand attack against the same opponent as a swift action. The attack penalty applied to this off-hand attack is double the normal two-weapon fighting off-hand penalty. You cannot benefit from this feat if you already make more than one attack on your turn, as by using the full-attack action.
Special: An 8th-level monk with the flurry of blows class feature is treated as having both the Two-Weapon Fighting and Improved Two-Weapon Fighting feats in regards to meeting the prerequisites for this feat, and calculates his off-hand attack roll as though he had the Two-Weapon Fighting feat, despite not making a flurry of blows.