A. When the water temperature is ≤29c,
   Blue will show automatically;
B. When the water temperature is between
    30c~39c,Green will show automatically
C. When the water temperature is between
     40c~49c, Red color will show automatically;
D. When the water temperature is ≥53c, RED
     color will flash automatically
or
1、As the built-in device generating electricity without the battery and any other power connets to water, LED will emit the light.                
2、The light can change one color every 3 to 5 seconds so that the rainbow colors are showing gradually.
HM-D002-1: 254*254*8mm
HM-D003-2:300*300*8mm
HM-D001-2: 198*198*10mm