Arc'teryx Experimental Tango Rucksack Foliage Green

USMC ILBE test/prototype backpacks, designed by Arcteryx and manufactured by Propper.

It seems even bigger than the issued ILBE. Measures 36 inches from the bottom to the top of the extender. Weighs about 8 lbs 4 oz. Rare early test version dated 2003.