These vests were originally designed during the Vietnam War to carry 40mm grenade rounds for the M-79 grenade launcher, and later the M203. These vests were used through the 1990s for grenadiers.
The top pouches are longer to accommodate flare cartridges, while the rest are meant for HE rounds. These particular vests are dated in the 1980s, but are identical to the ones used during the later years of Vietnam. These are in Excellent unissued condition and are constructed of heavy duty nylon.