KC-L50-W Made in 2020 SHARP Humidifying Air Purifier, Filter Included, With Instruction Manual. - Brand: SHARP - Model: Air Purifier - Features: Filter Included - Condition: Detailed Cleaning Completed After purchasing, I stopped using it within a month, and it has been stored at home for many years after cleaning. This week, I disassembled it again and cleaned the details, but the blue filter was soaked in citric acid for 3 hours and gently scrubbed with baking soda, but the dirt did not come off completely _(._.)_ Thank you for viewing.