... polarity protect test,EMC anti-jamming test and high/low temperature condition operating testbefore it is on ... -2. 9007-2 hid for low beam and halogen bulb for high beam, with 2ballasts and installation ... 9007-3, single HID can switch between high beam and low beam,with 2 ballasts and installation clamps. ... HID bulbs on each bulb, which works for high and lowbeam, with 4 ballasts and installation clamps ...