The Signal Corps insignia is two crossed signal flags with a flaming torch of gold. The "crossed flags" have been used by the Signal Corps since 1868, when they were prescribed for wear on the uniform coat by enlisted men of the Signal Corps. The flags and torch are symbolic of signaling or communication.
The enlisted insignia is a gold-colored disk with a second disk that has 'U.S.' superimposed and both disks are worn on enisted uniforms.