Mummy sleeping bag is two-way zip useful for easy opening when ventilation is required. Stick your feet, soft touch & breathable silk-like polyester material is used for lining. Mummy Bags are all Two Way Zips for easy opening ventilation and are joinable, so bags can be zipped together. Click HERE for LEFT ZIP Mummy Bag. NOTE: To make it easier to unzip when you are in it, choose a bag where the zip opening is the opposite side to your leading hand. If you are right-handed choose a Left Zip bag; if you are left-handed choose a Right Zip bag.