Different types of electric light sources have different structures, but generally have the following parts: filaments, electrodes, phosphors as illuminants; glass, translucent ceramic tubes, quartz tubes as illuminator shells; Guide wire, stem, lamp holder; various gases, mercury, metals and halides as fillers; getter, various coatings, insulation and adhesives. There are 6 main performance indicators of electric light source]: 1 light quantity characteristic index. Including total luminous flux, brightness, light intensity, amount of ultraviolet light and amount of heat radiation. 2 light color characteristics indicators. Including light color, color temperature, color rendering, chromaticity and spectral distribution. 3 electrical characteristics indicators. Including power consumption, lamp voltage, lamp current, starting characteristics and interference noise. 4 mechanical characteristics. Including geometric dimensions, lamp structure and lamp holders. 5 economic characteristics. Including luminous efficiency, life, price and electricity costs. 6 psychological characteristics. Including the appearance and comfort of the lamp. Lithium Cordless Drill,Wood Jig Saw Hand,Battery Drill Tools Shanggong Power Tools Factory , http://www.ulite-powertools.com