14mm Quartz Thermochromic Bucket / Color Changing Quartz Bucket. While adding a thermal conductivity material in the quartz bucket, when the temperature is a color, the color also changes with the temperature, the cooling time is back to the original color, so a gradual process, according to the display color. Yellow=Cold Red=Hot
Color Changes to orange around 300-350 Degrees Red= Hot Orange=Just Right Yellow=Cold