Mountain Hardwear Ultralamina 15 Sleeping Bag Mummy shape design reduces girth in unnecessary areas to ensure a lightweight frame that hugs the body. Wave-like design of the insulation enhances loft as well as warmth for a softer, more comfortable sleep. Welded seams keep the filling in place while denying entrance to moisture, wind and other outdoor elements. Half-zippers provide dual entry and versatility to use the sleeping bag as a blanket when sitting up. Thermic Micro fill is both warm and compressible for comfort and packing ease.