Yellowstone Fleece Mummy Sleeping Bag Liner - Multi-colour The great thing about a sleeping bag liner is they keep you cool in the summer and warm in the colde If you are new to camping, the temperatures can be a bit of a shock and having a liner will help en It's lightweight and compact, so taking it trekking or to a festival is easy Buy this product as you will be warm and comfortable It even increases the longevity of your sleeping bag