Big Agnes Buell 30 Synthetic Sleeping Bag SYNTHETIC FILL TRADITIONAL MUMMY BAGS FOR THOSE WHO PREFER A BAG WITHOUT AN INTEGRATED PAD SLEEVE Traditional mummy bags are designed to be taken anywhere and provide sleep for the weary by providing a cozy fill and a roomier mummy shape than a traditional bag design. Lightweight enough to stuff in your pack for summer backpacking but comfortable enough for backyard camp outs with the kids, these bags are so versatile and comfortable you'll want to take them on every outing.