Huh, I was not aware of that... I'll have to make sure our Wizard is aware of this, since there's a lot of times where an enemy Wizard or Sharpshooter might try to take the Wizard out at range with an attack targeting a non-AC defense. So now Staff has an even bigger leg up on the Wand.
Staff of Defense: A staff of defense grants you a +1 bonus to AC. In addition, once per encounter as an immediate interrupt, you gain a bonus to defense against one attack equal to your Constitution modifier. You can declare the bonus after the Dungeon Master has already told you the damage.