The tropical rucksack is a nylon version of a cotton rucksack for ARVN forces. It has a longer back and more capacity.  It is also more desirable than the lightweight rucksack because it weights less and has fewer projections to snag on the underbush. 
The rucksack consists of a pack with drawcord closure and three outeside pockets, and is mounted on a spring steel X-back frame with lumbar pad and quick release shoulder straps. Each pocket has an adjustable closure and snap fasteners which allow quick access. Equipment hangers are located above each pocket; each hanger can accommodate equipment with double end hooks or sliding keepers. The pack top flap (which serves as a waterproof cover for the pack) is also a pocket. This top flat pocket has a nylon hook-and-pile closure. The two loops on the bottom and two on each side of the pack are used to attach items to the pack. An equipment hanger, with tiedown strap, is also located on each side of the pack.
- RUCKSACK, TROPICAL W/3 SMALL LINERS, AND 1 LARGE LINER
- ↑ Kennedy, Stepehen; Goldman, Ralph; Slauta, John. (May 1973). The Carrying of Loads within an Infantry Company. Natick,MA: Clothing and Personal Life Support Equipment Laboratory, US Army Natick Laboratories. [pdf]
- ↑ TM 10-276. 1970. page 26.
- ↑ size 1 and 2 of MIL-L-43720
- ↑ https://books.google.co.jp/books?id=I3-oDQAAQBAJ&lpg=PA41&pg=PA41#v=onepage&q&f=false
- ↑ https://hdl.handle.net/2027/mdp.39015078436980?urlappend=%3Bseq=312