circle-down dollar cancel-circle cart search external menu close

Backpack Subsystem

The modified commercial Backpack Subsystem (UM21) contains a backpack, patrol pack, and butt pack. The backpacks state-of-the-art internal frame affords a stable platform sufficient to carry 120 lbs. effectively. The backpack transfers load efficiently from the shoulders to the waist and provides adjustments to fit the 5th - 95th percentile male SOF operator. The butt pack attaches to ELCS or the backpack; the patrol pack attaches to the backpack, and is compatible with the other SPEAR BALCS components.

SPEAR backpack with side pocketsSPEAR backpack with side pockets


  • Backpack
    • weight: 13 lbs.
    • volume:
      • top compartment: 592 cubic inches
      • main compartment: 3042 cubic inches
      • sleeping bag compartment: 1775 cubic inches
      • side pockets: 1692 cubic inches
    • load capacity: 120 lbs.
  • Patrol pack
    • weight: 6 lbs.
    • volume: 1945 cubic inches
    • load capability: 50 lbs.
  • Butt pack:
    • weight: 2 lbs.
    • volume: 507 cubic inches
    • load capability: 20 lbs.


  • UM21 Universal Military Backpack Subsystem Use and Care Manual [pdf]