Western Mountaineering designed its TerraLite Sleeping Bag for comfortable sleeping whether we're camping or ultralight backpacking. Weighing in at only one pound and thirteen ounces, the TerraLite owes its lightweight quality to the 850+ fill premium goose down insulation that keeps us warm on the chilliest summer nights. The continuous baffle construction ensures the down doesn't isolate to one side, and the bag's comfortable mummy shape includes a wider mid-section that allows you to sleep on your side comfortably.