Used for about 10 days after purchasing new. It's the current model HD RX324 WK. Made in 2024. Includes the instruction manual and other items as shown in the photos. I also purchased a large-capacity humidifier around the same time, and since that one is sufficient for humidifying, I no longer need this one. Used in a 2-year-old new construction building, with no pets. The exterior has no noticeable chips or dents. The filter has some slight water scale buildup, despite only 10 days of use. Photos 4 and 5 show the top and bottom of the filter, respectively. I cleaned it with citric acid, so it's clean, but if you're concerned, please replace the filter at your own expense. Price includes shipping, so please refrain from price negotiations.