Greater Armor Material Focus (3.5e Feat)
From D&D Wiki
Greater Armor Material Focus [General, Fighter]
Choose a special material (Such as adamantine or dragonhide). While wearing armor crafted of that material, you move easier.
Prerequisite: Base Attack Bonus +8, Armor Material Focus (3.5e Feat)
Benefit: When wearing armor made of the specified material it inflicts one less armor check penalty and the maximum Dex bonus is raised by one. This cannot reduce the penalties to sub-zero levels.
Special: You can gain this feat multiple times. The effects do not stack. Each time you take the feat, it applies to a new type of material. A fighter can select this feat as one of his bonus feats.