A backpack — also called bookbag, kitbag, knapsack, rucksack, pack, sackpack or backsack — is, in its simplest form, a cloth sack carried on one’s back and. Stay warm, dry and pack light: Learn how to buy an ultralight sleeping bag & reviews on the best models from top brands. We review & research, you decide. Rated 5 out of 5 by TheRealJLo from A Thanksgiving Miracle The Ratio 15,…