You conjure a shimmering silver shield, which you can then move around the battlefield to provide protection where it is needed most.

Encounter   ✦     Conjuration, Divine
Standard Action      Ranged 5

Effect: You conjure an astral shield in 1 square within range. The shield lasts until the end of the encounter. You or any ally gains a +2 bonus to AC while in the shield's square or adjacent to it. The shield can't be attacked or damaged.

  Move Action: You move the shield up to 3 squares within range.

Published in Player's Handbook, page(s) 68, Class Compendium.