As expected from the mountain-oriented ROC product family of Haglöfs products, this bag is full of thought-out detail and top notch materials. All fabrics are different versions of Pertex Quantum, and the down insulation has an impressive fill power rating of 800. Haglöfs is also known for great sleeping comfort. The soft hood and thermal collars keep your body heat from leaking out as you move when breathing and turning sides. While the liner fabric is soft and extremely breathable, the surface fabrics are durable and offer some protection from the moisture you easily find condensating on the inside of a shelter. The two-way central main zipper is luxurious for side sleepers: you'll never find your weight resting on it, and the internal insulation baffle always stays in place. The trapezoidal baffle structure minimizes the formation of cold bridges, and makes use of all the insulation the down has to offer. The size number refers to the user's max. length - Mountain fit: no exces