Your helm protects you from hard hits.
Benefit: When wearing a helmet, you add +1 to your AC against critical hit confirmation rolls. When a critical hit is confirmed against you, as an immediate action, you can apply half of the damage from the attack to your helmet rather than yourself, applying hardness as normal. If the damage destroys your helmet, any leftover damage is applied to you. After using this feat, you are staggered until the end of your next turn. You may not use this feat if your helmet has the broken condition or the attack ignores armor bonuses to AC.
Pathfinder Roleplaying Game Advanced Race Guide © 2012, Paizo Publishing, LLC; Authors: Dennis Baker, Jesse Benner, Benjamin Bruck, Jason Bulmahn, Adam Daigle, Jim Groves, Tim Hitchcock, Hal MacLean, Jason Nelson, Stephen Radney-MacFarland, Owen K.C. Stephens, Todd Stewart, and Russ Taylor.