Mummy: They offer high thermal efficiency due to their narrow design, which reduces air gaps and heat loss. They are lighter than rectangular ones, as they use less material. Recommended for hiking, mountaineering, or extreme temperatures.
Left: It not only concerns the ability to connect with another sleeping bag but also ease of use. The zipper on the left side as you lie down is more convenient for right-handed people.
Right: It not only concerns the ability to join with another sleeping bag but also ease of use. The zipper on the right side as you lie down is more convenient for left-handed users.