Your specialized type of armor better protects you from damage and is much more comfortable to wear.
Prerequisites
Armor Focus with selected category of armor, base attack bonus +4.
Benefit
Choose one type of armor included in the category of armor for which you have already selected the Armor Focus feat. While wearing armor of the selected type, increase the maximum Dexterity bonus of the armor by 1 and the damage reduction of the armor by 2 and lessen the arcane spell failure chance by 10%. In addition, your movement speed is no longer reduced by wearing armor of the selected type.
The benefits of this feat stack with those from Armor Focus.
Special
If you possess the armor mastery ability, the benefits of this feat stack with that ability.
You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new type of armor.