What’s the DC for Hatchling’s Flame?

Saving Throw: Reflex half

You focus a burning aura of energy at the end of your blade. It forms a seething sphere that, after a moment, bursts into a torrent of energy.

The Desert Wind discipline teaches its students how to unleash their ki as burning energy. This maneuver allows you to create a wave of fire that sweeps over your enemies. When you initiate this maneuver, you blast forth a cone of flame that deals 2d6 points of fire damage. This maneuver is a supernatural ability.

Out of the 3 "X’s Flame" maneuvers of Desert Wind, Hatchling’s Flame is the only one that does not specify a DC even if it says "Saving Throw: Reflex Half", so, what’s the DC?