You can use your shield to prevent an opponent from making attacks of opportunity against you.
Prerequisite: Shield proficiency, Base Attack Bonus +3
Benefit: You must be using a heavy or tower shield to benefit from this feat.
Each round as a free action, you may select one opponent to protect yourself from. Until the end of your turn, you do not provoke attacks of opportunity from that opponent due to your movement.
Advanced Feats: The Cavalier’s Creed