SRD:Shapeshifter's Armor

Shapeshifter’s Armor
This suit of +6 hide armor grants its full Armor Class bonus regardless of any form the wearer takes (with polymorph, shapechange, wild shape, or similar abilities).

Caster Level: 21st; Prerequisites: Craft Magic Arms and Armor, Craft Epic Magic Arms and Armor, shapechange or wild shape ability; Market Price: 400,165 gp; Cost to Create: 200,165 gp + 14,000 XP.