The CRT monitor is one of the main classic monitors in history also to be one of the first ones. The CRT monitor is a glass vacuum tube screen that inside of it has a charging cathode. CRT monitors are used in hospitals and one of their main purposes is helping to restore the normal rhythm of the heartbeat in a patient. Although these monitors look helpful in life, they use harmful radiation when creating images in the screen. This can be solve by applying lead into the glass to manufacture the glass components in the screen. The approximate amount of lead added into the glass is 4 pounds of lead per CRT. Overall, CRT monitors are basically the classic monitors that were used back then, but some are still being used nowadays and still have some purposes that could be used in other places as well.