Freedom of movement and cozy warmth: the sleeping bag with arms and legs ensures a comfortable sleep, because you turn and move naturally during sleep.
Not only for sleeping: the zipper openings on the hands and feet also allow you to grab objects or walk around. Thus, the sleeping bag does not constrict.
For indoors and outdoors: the mix of pajamas and sleeping bag is perfect for camping, longer evenings around the campfire and many other occasions.
