How to Choose a Down Sleeping Bag
Down sleeping bags use duck or goose down, the fluffy feathers birds use for insulation. As of yet, no made-made fiber has matched the warmth-to-weight ratio of down. Compressible and lightweight, down is the choice for traveling small and light. Look for the EN, or European Norm, rating. This industry-wide standard gives you an idea of the lowest temperature at which a bag will keep you warm.