Warblers are anti-gunfire devices invented by Max Epper.
Before Seven Ancient WondersEdit
Epper sold them to the U.S. military, but, thinking they knew better, the Americans attempted to rework the Warblers, prolonging their use. Being their inventor, Epper kept several prototypes for himself.
On his way to the Sixth Vertex, Jack rigged up the Halicarnassus with several Warblers, which when powered by the plane created a huge magnetic field around the plane. This allowed him to fly the plane in towards Easter Island without having to worry about the anti-aircraft fire from the Chinese.
Warblers emit a magnetic field that deflect all supersonic metallic flying objects within its range, namely bullets. However weapons such as RPGs are too heavy for the magnetic field to deflect. They also disrupt radio signals when active, and also deflect the bullets of the people using the Warblers, forcing them to use rubber bullets. They are roughly the same size as a grenade.