Perfect Reflexes

 
Prerequisite(s): Base Reflex Save 6+, Combat Reflexes, Lightning Reflexes
 
Benefit: You can still make an additional number of attacks of opportunity per round equal to your Dexterity bonus, but now you can make more than one attack of opportunity per round against a single enemy. You still may only make one attack per provocation. For example, you have a Dexterity of 17 and Perfect Reflexes. A hasted enemy moves more than 5ft. within your threatened area, provoking an attack. He continues to move another 5ft. within your threatened area, provoking a second attack. He casts a spell, provoking a third attack. Then he uses his partial action from haste to move out of your threatened area, provoking a fourth attack. You could have attacked him all four times.
 
Source: Beyond Monks