M109 howitzer

The M109 is an American 155mm turreted self-propelled howitzer first introduced in the early 1960s to replace the M44 and M52. It has been upgraded repeatedly since, most recently to the M109A7 standard, and the M109 family remains the most common Western indirect-fire support weapon fielded by the maneuver brigades of armored and mechanized infantry divisions. The vehicle carries a crew of four: the section chief, who also commands the vehicle, the driver, the gunner, and the ammunition handler and loader.