Abstract: The purpose of the thermos, the subject of the invention, is to hold two different liquids, which are needed to hold their temperatures, without mixing them in separate parts by developing a usage system which the existing thermoses don't have. Another purpose is to pour the liquids without mixing them when they are needed to be poured. Said product is configured as a modular set which has thermoses with different volumes. Because main cap system is adaptable to main bodies with different sizes, thermoses with different volumes can be formed.