Cold cathode germicidal lamps are designed with small structure, long life and low lamp power, they emit 254nm (ozone free), or 254nm and 185nm (ozone generating) to kill microorganisms, only operating for several minutes, so they are extensively used in sterilizers for toothbrush, make-up brush, mite predator, vehicle disinfection devices, vacuum cleaners etc.. There are two types used commonly, Linear germicidal lamps (GCL) and U-shaped germicidal lamps (GCU).