A Rebuildable Dripping Atomizer or RDA for short, is used in a mechanical mod or box mod. The design is very basic. The whole idea is to be able to make or "build" your own coils. The RDA ususallly has 3 post that you are able to insert your leads from your coil into and then tighten down when in place. After building and inserting your coils, you then would want to put a wicking material through or around the coil, so that juice (drops) or e-liquid is able to be absorbed by the wicking material. When the coil ignites and vaporizes the juice from the wicking material, the wicking material will naturally pull more juice and draw it near the coil. The reason why they are called "dripping" or "dripper" is because, that is what the person has to do to inject more juice to the wick. Most people drip right into the drip tip to get the wick re-saturated. Wicking material comes in many shapes sizes and material types. We here at Atomic Vapor have learned that the best wicking material is organic cotton. And the best organic cotton in our opinion is Japanese cotton because the cotton fibers are more integrated and easier to cut and work with.