AN M8

The AN-M8 Smoke Grenade designated as the Army/Navy Model 8 HC Smoke Grenade (AN-M8 Smoke HC) is a U.S. military grenade used as a ground-to-ground or ground to air concealment or signaling device.

Developed in the 1940s, using a sheet-steel cylinder body that can emit a dense cloud of white smoke that would last from 105 to 150 seconds.

The AN-M8 was used extensively by American or other allied forces used throughout World War II to the present.

It is used for smoke screening, target marking, and signalling, although the M18 colored smoke grenades are mainly used for the latter.

When employing the M18 or AN-M8 HC hand grenade, it may be desirable to use one of these grenades without the fuze. To do this, the following procedure should be used in combat only:

...
Wikipedia