CSI & UV 365nm Flashlight
Ultraviolet, abbreviated as UV, is an electromagnetic wave with a wavelength between 100 nm and 400 nm. Electromagnetic waves do not need to rely on the medium to propagate, and their propagation speed is the speed of light in a vacuum.
Electromagnetic waves can be classified by frequency, from low frequencies to high frequencies, including radio waves, microwaves, infrared rays, visible light, ultraviolet rays, X-rays, and gamma rays. The electromagnetic wave that the human eyes can receive, with a wavelength between about 380 and 780 nm, is called visible light.