The signal flare (煙弾 Endan?) is a common tool used in the Military by the Garrison Regiment and the Scout Regiment. The signal flare has a variety of uses, depending on the mission and brigade using them.
While the signal flare has many uses, its main purpose is long distance communication. The Garrison uses it as a way to inform the higher-ranking officers how their mission is going, while the Scout Regiment uses it as a way to communicate (often in the presence of Titans) to the rest of the legion. Soldiers may improvise by using the flare to conceal allies from enemy sight or to stop fast moving Titans. Levi's squad used it alongside oil barrels to create a huge amount of smoke so that the Anti-Personnel Control Squad could not see them.
The ammo comes in pre-loaded barrels that are locked into place on the pistol. After being fired, the barrels are discarded and replaced before being capable of use again. There are various types of ammo and usage depends on the mission and message at hand.
The ammo the Garrison Regiment uses is the following:
- Green - Mission started.
- Red - Mission failed. (Unless a yellow flare is spotted some time after a red)
- Yellow - Mission successful.
- Red - Titan spotted.
- Black - Abnormal Titan spotted.
- Purple - An emergency of some kind. (someone is grabbed, etc.)
- Blue - An order to retreat.
- Green - Change direction of the formation: Fired by the commander in one direction to indicate a change in the direction, and then repeated by the relay soldiers.
- Yellow - This lets everyone know that the mission has been terminated, be it successfully or failed.
- Acoustic - While leading the Female Titan through the Forest of Giant Trees, Captain Levi used a special shell that emitted a high-pitched noise.