You always have cover against ranged attacks when using a shield.

Prerequisite(s): Kappa, Greater Shield Focus, Shell and Shield

Benefit: When equipped with a shield, you gain cover against ranged attacks (+4 AC and +2 Reflex save), so long as you are not in melee. When in melee, and equipped with a shield, you gain partial cover against ranged attacks (+2 AC and +1 Reflex saves).

These bonuses do not stack with the bonuses granted by Greater Shield Focus and Shield Focus.