Superior Orb of Clear Air (3.5e Equipment)

Superior Orb of Clear Air
 An unusually large and potent orb of clear air, the method to create these is a well guarded secret lost to time. They are the size of a person (5 ft) and the mists they produce seem more like dark and foreboding storm clouds. However, they automatically adjust the size of their air shell to the structure it is embedded within, regardless how large it is (out to a distance of 20 ft outside the edge of the vehicle or building). It must be an artifical structure, so embedding it into the planet does nothing.

The effects generated are much stronger. Temperatures from incoming air are adjusted instantly instead of over 10 minutes. Large and dense objects still come through, but the force field is now strong enough to keep out water up to a pressure depth of 1000 ft, at which water begins leaking through. As a result most liquids stop at the force field's edge as well.

These artifacts are usually equipped on huge buildings, flying castles, and other prohibitively large structures.