Sea to Summit Watercell X

The Sea to Summit Watercell X is a collapsible water bag made from recycled nylon with a TPU liner, listed here at 4 litres and 170 g, though Sea to Summit makes it in sizes from 4 to 20 L for different camp needs. The 63 mm wide-mouth Nalgene-compatible opening makes it easy to fill from a lake, tap, or funnel and to scrub clean, and a one-handed flow-control cap lets you dispense water without needing a second hand to hold or tip the bag. It's BPA/BPS-free and also works as a camp shower when hung up, which makes it more versatile than a simple dromedary bag for base camp or car-camping setups. At 170 g for 4 L it's not an ultralight item to carry full of water on the trail - it's better suited to basecamp water storage, group cooking, or a camp shower than as a bottle substitute for hiking with water on your back.