Handheld air quality monitor that can measure PM2.5, temperature, and humidity. Purchased on Amazon in 2021 for 9999 yen. Used only once. Operation confirmed. Includes box and instruction manual. - Product Name: VSON Air Quality Monitor - Product Size: 7.1 cm - Measurement Functions: PM2.5, PM10, HCHO, TVOC - Display: Color display - Usage: Handheld The following is a quote from the Amazon purchase description: VSON Air Quality Monitor White Air Quality Meter Test Formaldehyde HCHO TVOC PM2.5 Quality Pollution With Indoor Air Quality Measurement (White) * Brand VSON * Color White * Item Weight 200 grams * Product Dimensions (L x W x H) 15.1 x 4.4 x 7.1 cm * UPC 739210348694 * Manufacturer VSON * Multi-functional air quality monitor This multi-functional air quality tester can be used not only to detect formaldehyde in the air, but also to detect TVOC, PM2.5, and even PM10. It has the function of air quality assessment, and the results of the air level are displayed on the LCD screen. * 3 independent sensors It features 3 independent sensors and an innovative light-sensing refraction algorithm that greatly improves its detection accuracy and speed. * Easy to operate. One-click operation for convenient use. This air quality monitor comes with a USB charging cable and a built-in lithium battery. These have a long life and can be recycled. * Lightweight and durable with a rear bracket. The high-quality lightweight shell with a clear LCD display will bring you a pleasant experience. Thanks to the rear support bracket, the monitor can stand, and the data is visually visible. * Let's live in a healthy environment. You can use it to track the quality of the surrounding air. In addition, the air quality sensor can be used for air quality testing in homes, cars, or offices.