Staying Warm at night while out in the mountains is one of the most important goals of any outdoor enthusiast. We at Winterial wanted to create a lightweight and effective sleeping bag for the ultimate adventure. We have created a sleeping bag that will give you the comfort that you need when youre sleeping underneath the stars during those freezing nights. The Winterial 15 Degree Mummy Bag is rated to withstand nights that fall to 15 Degrees Farenheight. The bag is constructed with 100% polyester. It was created with durable zippers that was meant to last for years of use. This particular bag is ideal for any season: winter, spring, or fall camping. It will keep you warm while your friends and cold and jealous. Take a Winterial Mummy Bag on your adventure and experience the best camping or climbing experience of your life.