Auran Mask: This mask fits over the character's nose and mouth. The bulk of the item is a cloth packet holding a porous, sponge-like alchemical substance. It requires a move action to put on or remove, and once a single breath is taken through the mask, its benefits last for one hour (or less if taken underwater).
A creature wearing an auran mask receives a +5 alchemical bonus on Fortitude saves against inhaled toxins. In addition, the wearer can breathe underwater as if under the effect of a water breathing spell, though immersing the auran mask in water reduces its remaining duration to 10 minutes (or less, if less than 10 minutes remain). Source: Complete Mage pg. 134, Alchemical Items. Cost for Auge to create 28g, 5s. (Hoard value 60g) DC25.