You call a piece of armor or a shield 'from thin air' to you. (Actually, it is a real item hailing from some other random location in the space and time.) You don't have to see or know of the item to call it—in fact, you can't ever call a specific item; you just specify the kind (chain shirt, full plate, buckler, or some other). The item is made of ordinary materials appropriate for its kind. Armor appears correctly donned and shields appear on the proper arm. If the armor is ever off your body or you relinquish your grip on the shield you called for 2 or more consecutive rounds, it automatically returns to wherever it originated. (For this purpose, you're considered to be wearing armor when you're donning or shedding it.) Armor and shields gained by call armor are distinctive due to their astral glimmer.
For every 4 additional power points you spend, this power improves the item's enhancement bonus to Armor Class by 1. For example, if you spend 13 power points, you call a shield or piece of armor with a +3 enhancement bonus to Armor Class.