90% white duck down, high down content, good warmth retention. Because down is an animal protein fiber, it has higher heat retention than cotton (plant cellulose). In addition, the spherical fibers of down are densely covered with thousands of tiny triangular pores, which can shrink and expand with the change of temperature to produce a temperature-regulating function, which can absorb the flowing heat emitted by the human body and isolate the invasion of cold air from outside.