The USMC FILBE main pack bag is the primary rucksack used in the Family of Improved Load Bearing Equipment system. Designed for extended field operations, it offers high capacity storage with multiple compartments for organizing gear.

• Color: Coyote brown
• Capacity: Approximately 80–100 liters
• Compatibility: FILBE frame, shoulder harness, and hip belt
• Features: Multiple zippered compartments and MOLLE webbing for modular attachment

Issued to Marines as the standard large rucksack for load carriage in the FILBE system.