Super warm and comfortable sleeping bag offered by OuYun Our design inspiration comes from the science of CS-GDP sleep development. is to promote adequate deep sleep for baby to grow better. With OuYun, you don't have to worry about the quality and effect. Our sleeping bag is made from naturally colored cotton which is organic.And usually has four types of thickness for every style to meet different temperature needs. What is Naturally Colored Cotton? It is cotton that has been bred to have colors other than the yellowish off-white typical of modern commercial cotton fibres.Colors grown include red, green and several shades of brown.The cotton's natural color does not fade. Yields are typically lower and the fiber is shorter and weaker but has a softer feel than the more commonly available "white" cotton. This form of cotton also feels softer to the skin and has a pleasant smell. It is still relatively rare because it requires specialized harvest techniques and facilities, making it more expensive to harvest than white cotton. Our cotton planting base belongs to temperate continental climate The obvious characteristic is that the climate is dry,less rainfall, evaporation, large and small temperature difference between day and night, sunshine time is long. Annual average rainfall of 39.9mm,is one of the best quality cotton producing areas in the world. OUYUN promise Our products are perfectly safe,friendly to environment and human body. No formaldehyde and No fluorescent agent added. All passed GOTS international certification.