A downhole tool for circulating fluid in a well bore. When one side of the housing container is opened so that the first edge of the first plate may be separated from the third edge of the second plate, the first housing recess of the first plate appears and stacks of tags or memo papers housed therein can be dispensed. The compartments maintain their respective contents separately from one another for purposes of transport, storage andor sterilization. The field emitters are located on surfaces of the carriers, respectively.