Camelbak LifeStraw Reservoir Gravity Kit Description: An essential accessory for any camper or outdoor enthusiast, the Reservoir Gravity Kit clicks into place with ease to convert the Crux(R) 2L Reservoir Filtration Kit into a gravity bag. The Gravity Kit includes a U-shaped tube that connects the reservoir to the filter in a downward orientation via the easy-to-use Quicklink(TM) system. A secondary tube extends from the filter body and has an on/off valve allowing for steady flow water delivery. Hang the fully assembled reservoir and allow gravity to provide reliable and clean drinking water.