M-61 Individual Field Pack This is the later version that has the rubber collar liner and is larger than the M-56 version. this is the most common field pack in the mid to late 60
Repro Vietnam Era US Army M-56 Butt pack - New from Hessen Antique
アメリカ陸軍・M１９６１フィールドパック アメリカ軍ベトナム戦争コットン装備バンダリアM16ライフルM4ライフル小銃剣(個人装備)｜売買されたオークション情報、Yahoo!オークション(旧ヤフオク!) の商品情報をアーカイブ公開 - オークファン（aucfan.com）
US draagstel LC2 Suspender LC-2 - origineel US Army, Uitrusting & Overig
US Army M-61 INDIVIDUAL FIELD PACK (BUTTPACK) draagtas - Groen (replica), Rugzakken & tassen
U.S. Military Tactical M81 Woodland M67 Field Butt Pack Repro – GRANDPOPSARMYNAVY
1956 Equipment
Vietnam War - U.S. M1956 Field Pack 1st Pattern - M1 Militaria
buttpack Mark Deux by Brigadierwolf -- Fur Affinity [dot] net
Vietnam War - U.S. M1956 Field Pack 1st Pattern - M1 Militaria
U.S. M1956 BUTT PACK COMBAT 1961 VARIENT NEW
US Army M-61 INDIVIDUAL FIELD PACK (BUTTPACK) draagtas - Groen (replica), Rugzakken & tassen
Uitrusting & Overig Military Collectibles 4U