Grüezi Bag - The Faithful Downwool Jacket This is what the ALPIN team says about our jacket: We already know the downwool filling from the sleeping bag sector. A functional insulation material made from wool (30 percent) and down (70 percent). The idea behind it: the down provides the insulation, the wool absorbs the insulation moisture up. GrüeziBag has now used the same material in the Faithful jacket in places where insulation is important. Pure alpine wool (Lavalan) is used in areas where there is a particularly high level of moisture, for example under the arms and on the collar. With this mixture, the jacket is not super light and also not as fluffy as some pure down jackets. But the wearing comfort is excellent and even if it gets a bit warmer, you don't have to take the jacket off straight away (as you should with a down jacket).