Car HID Xenon Telescopic Light Conversion Kit - 2 pcs 9007 Xenon HID Bulbs Lamps Lights 4300K Swing Hi/Low Lamp adopts a Pulse Motor to accurately simulate the luminous point of the stock halogen bulbs inside the housing ,with less than 0.1mm error. It has the following merits:disting change of light when switching between high and low beams, strong self-locking function,less heat ouput,higher light-output at high beam,etc. Relay harness adopts sepatate citcuit for each lamp,making sure that both lamps do not go off at the same time in the case of failure .