RDA stand for Rebuildable Dripping Atomizer. These are for use with wire coils and cotton. RDA's are for advanced users. Please make sure you are able to build and maintain before purchasing. We are able to help with first time RDA purchases if you would like to call or email us. YouTube is also a great way to see one and get an idea of the care needed for maintenance.
Note: These items are only available in-store due to local laws, taxes, and regulations regarding electronic cigarette devices