Yupoo MOOSE KNUCKLES has always been recognized as the warmest down jacket. Various Instagram celebrities wear it all the time for street photos, but they still can't get rid of their love for it. No matter how cold the weather is, there is no need to be afraid because it is filled with 90% white duck down, which is a legend. The warmest down jacket in the world is known as a must-have for arctic outdoor sports. The world's most popular down jacket. Major celebrities are rushing to buy the must-have women's model in sizes XS to XXL.