Synthetic insulation used to be synonymous with heavy and bulky; not so with the Mountain Hardwear Lamina 0 Degree Synthetic Sleeping Bag. The Thermal. Q polyester fill is highly compressible, maintains its loft, and performs far better than down in wet conditions, which makes this bag an obvious choice for backpacking in cold, wet climates. Lamina construction attaches the face fabric of the bag directly to the insulation, eliminating cold spots caused by typical baffle construction, while the standard mummy cut provides utmost efficiency in insulation. With a zero-degree rating, this Lamina makes a great option for those looking to snag one bag and one bag alone, since it works for mild winters, but you can easily unzip the two-way zipper for regulated cooling if you're using it year-round.