1.HID lamp means high intensity discharge lamp. 2.Luminescence's theory of the HID. Filled the HID's luminous pipe with Xe and metal halide, blazing with the high pressure,pipe will produce a steady arc, discharge the electricity and illuminate. 3.HID's advantages: a.HID's consuming power is 35w, which is half of the consumption of the tungsten lamp (65w),so it saves the oil. B.The luminous flux of HID is the tripe of the tungsten light,which can be 3000 lumen.It is brighter than the tungsten lamp. c.The life span of HID is about 2500 hours, which is ten times of that of the tungsten lamp. 4.there are many kinds of color temperature for you choice, : 3000k,4300K,6000K,8000K,10000K 12000k 5.main models include: H1,H3,H4,H4h/l,H7,H8, H11,9001,9004,9005,9006,9007,9007h/l, D2C,D2S,D2R