A medium-sized backpack. The original prototype was EAGLE's famous AIII backpack. Later, all major manufacturers launched three-day backpack products under their own brands. Foreign companies include Tactical Tailor, London Bridge (LBT), etc., and domestic companies include Xiangye, COMBAT2000, Phoenix Industries, etc.

A backpack generally used to carry ammunition, food and personal items for 3 days.

Based on the A-III backpack, this backpack adds a MOLLE webbing system around the periphery of the backpack, making it easier to mount other small bags and more convenient to use.

The backpack itself has three layers, a main bag, an auxiliary bag, and a small outermost auxiliary bag (one side bag can be hung on the left and right sides).

There is also a lining bag inside the main bag, which can hold a 3-liter water bag and lining.

The shoulder strap is lined with EVA to improve the comfort when carrying it.

The waist strap can be adjusted in length and disassembled as needed.