FDA approved Self-Check Temperature Patch. Measures body temperature by changing colour from small patch sticker. When attached, the color of the band changes with body temperature. For normal body temperature, it turns green. If it turns yellow, it means that you have a high fever of more than 38.5 degrees, so you need to see a nearby medical institution.It is used by attaching it directly to places where body temperature can be easily transferred, such as wrists and neck areas. (However, may vary depending on skin condition and body part.)- Korea's first registration of a "color-marked thermometer" under the Medical Devices Act- FDA registration Number: D407551- Durable: remains effective for 3 -4 days and can withstand washing or shower.