The needed chemical is put into the very tiny cylinder type carrier, once contact water, the water will exchange the space and release the needed
chemical into the air. The chemical can be flavor powder or other materails,
Depends on the end use.
The material, such as peppermint, or rose smell materials are replaced and
released into the air, creating interesting atmosphere. For example, the jogger can smell refreshing smell of peppermint while jogging in the woods.