Features 2 pieces 9 inches long Convert OEM ballasts to work with aftermarket AMP HID bulbs DescriptionThis page is for one pair (2) AMP-OEM connectors to convert OEM HID ballasts to work with aftermarket AMP HID bulbs. These adapters that will allow you to use HID ballasts which were made for D2S/R bulbs with re-based HID bulbs instead. (ie Matsushita or Denso ballast with H1 HID bulbs) If you already have a set of OEM or D2S specific ballasts and are changing over to something like a Morimoto Mini H1 Projector, there's no need to buy entirely new ballasts to be compatible with the required H1 bulb types. One side twists into the standard P32-D socket just like a D2S bulb would, and converts the output to be compatible with AMP type HID bulbs. The length for these D2S/D2R Converter is approx 9", it is longer than almost all conventional 3" plug converters in the market so it is much easier to install.FAQPlease visit Relay wiring harness, adapter and LED flasher FAQ/tech support for more detail.