Maybe not used at all? The water area seems squeaky clean and there is no buildup on the metal parts inside. Comes packaged up ready to go in box! Selling all my YL oils & diffusers due to my husband having a reaction and moving towards herbalism as a result. Very happy to bundle and accept reasonable offers! I’m slowly uploading listings - if you want anything specific and you don’t see it, please add this item to a bundle then ask me any questions!