The HydraPak Seeker 3L is an ultra-light, durable water storage bag ideal for camnping, backpacking, hiking, and much more. The Seeker 3L is completely collapsible and can fold down ino the size of a fist when empty. A large 42 mm opening not only makes the Seeker 3L easy to fill, but also makes it compatible with most 42 mm threaded filters, allowing you to filter more water. Constructed from 100% BPA and PVC free material, the Seeker 3L is extremely light and durable. Volume: 3L Collapsible water storage Low-profile, durable, coated handle for easy pouring and carrying Leakproof 42 mm screw cap with tear resistant, removeable tether that also acts as a convenient carry loop Compatible with 42 mm threaded backcountry water filters and Katadyn BeFree Filter Large 42 mm opening makes it easy to fill and tethered screw cap prevents cap from getting lost Two load bearing side lash points, for attaching to your pack or setting up a gravity feed External capacity gauge allows you to track your hydration intake Made of ultra-durable, abrasion resistant TPU & RF welded seams Can be frozen or filled with hot water (max temp 60°C) 100% BPA & PVC free Includes a compact storage bag