1. UVA band, wavelength 320~420nm, also known as long wave black spot effect ultraviolet.
2. UVB band, wavelength 275 ～ 320nm, also known as medium wave erythema effect ultraviolet.
3. UVC band, the wavelength is 200 ～ 275nm, also known as short wave sterilization ultraviolet.
4. UVD band, wavelength 100-200nm, also known as vacuum ultraviolet.
UVC ultraviolet lamp (270nm): used for sterilization.
UVA ultraviolet lamp (395nm): used to see ultraviolet light, so as to watch whether the lamp is turned on.