It's just water weight... Well, water weight adds up quick. And even an empty water bottle takes up space in your pack. Take the Sea to Summit Watercell X 4L Reservoir with you on your next lightweight adventure. You'll save weight on the trip but still be able to fill up at the campsite.
Food-grade TPU
Filled – 11 x 8.5 x 4 in / 28 x 21 x 10 cm
Capacity – 4 Liters / 135 oz
Weight – 4.4 oz / 125 g
BPA-free
PVC-free
Taste-free
Flexible
Durable
Strong, Streamlined Grab Handles Double as Lash Points
Low-profile Fill Handle for One-handed Manageability
Abrasion-resistant
Collapsible