These are interchangeable lids that will fit the CTAL airpots (in any of the four sizes). Four colors are offered so that you can color-code the contents of an airpot. That is, you might only buy one airpot, but may want two different lids so that you can color-code whether the airpot contains coffee or merely hot water.
Note that each CTAL airpot comes with one lid, and you get to choose its color when ordering the airpot. This item allows you to purchase additional tops of whatever colors you’d like.