From the Manufacturer:
With large front/back volume ratios, a body-centered load is easy to achieve with these new cutting edge designs. Pack them correctly and your balance and posture are unaltered by the load.
This combines with the low pack weight to give the most efficient load carrying system with ultralight gear. The pack and pockets have waterproof dri-liners. The Balance Pockets are removable.Key Features:
Approx Volume: MT55: 37 + 18L (2257 + 1098 cu in)
Approx Weight: MT55: 1.49 kg (3.28 lbs)
Minimum Weight: (without dri-liners) MT55: 1.42 kg (3.13 lbs)
Key Fabrics: 420 HD nylon, 210D, 70D x 100D ripstop nylon