Insignia Description
A gold color metal and enamel device 1 1/8 inches (2.86cm) in height overall consisting of a black enamel disc bearing two orange enamel lightning flashes crossed saltirewise and extending over the disc, at the top between the lightning flashes a stylized white enamel magnolia blossom with three green leaves, in base surmounted overall a white enamel crescent with points up.

Symbolism
The crossed lightning flashes symbolize the unit’s ability to readily support with signal communications facilities. The three magnolia leaves and blossom, the state flower of Mississippi, represent the 845th Signal Battalion’s home area, Third U.S. Army, and the location of the organization’s last activation at Pascagoula, Mississippi. The crescent, a symbol of North Africa, refers to the unit’s campaign service in North Africa during World War II. The colors black and white are used here to symbolize day and night alertness, while orange is a colors used for Signal units.

History
The distinctive unit insignia was approved on 15 Apr 1969.

Source: The US Army Institute of Heraldry