For those of you who live in the wetter climates, finally a custom-fitted liner bag to keep your sleeping bag and clothes dry. These bags, specially sized to fit your Gossamer Gear pack (though they will obviously work just as well in similar packs), are constructed of industrial-grade 2 mil virgin polyethylene film, and meet FDA and USDA specifications. They have a gusseted bottom for that custom fit. Using a bag liner for protection allows you to minimize weight by protecting only those items that you need to, and by utilizing the pack to protect the liner, permits the use of lighter materials. To close the bags, just twist and/or fold over.