The ARVN (Army of the Republic of Vietnam) rucksack (also known as the Ranger Pack for the South Vietnamese Rangers who used it) was a canvas, external-framed pack produced in the United States for use by the armed forces of the Republic of Vietnam throughout the 1960s and early '70s. The pack saw use with ARVN forces, and became desirable amongst US troops in the early years of the Vietnam War, before the US military fielded similar items in the form of the Tropical Rucksack and Lightweight Rucksack, which were both influenced by the ARVN design.
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ARVN rucksacks were never an official item of United States military equipment. Those that saw service were either acquired individually or by units through trade or purchase with members of the Army of the Republic of Vietnam. In the first few years of United States involvement in the Vietnam War the M1956 Field Pack (butt pack) proved too small to carry combat loads, but the Lightweight Rucksack and the M1951 Mountain Rucksack in the inventory at the time were in high demand and short supply, so many units and individuals acquired ARVN rucksacks for use in the field. Many were replaced in United States military use during the later years of the Vietnam War by the Tropical and Lightweight rucksack as more became available. Examples that left Vietnam with US troops did so as souvenirs and did not see use outside of Southeast Asia.