This is the slim king of hydration backpacks that carries a big tanker of hydration for the extreme races
Features:

• Weighs only 340g (0.749lbs) excludes bladder weight
• NDM 4-point harness for a 100% bounce free fit
• Stretch support harness
• 3 liter Elite hydration bladder
• Water resistant phone pocket at the back
• Total number of pockets 2
• KC66 Edition – To Honor Kurt Caselli