L.E.D. Tail Lamp Conversion Kit. Positive Ground. Also order flasher unit 17-1120. Applications: MK II Later XK-150 (dual-lens tail lights) Later MK IX (dual-lens tail lights)There's simply no denying that cars are safer today by orders of magnitude. While you can't add air bags to your vintage Jaguar, you can upgrade the safety of your tail lamps with these nifty Light Emitting Diode (LED) tail lamp inserts. The difference in brightness is incredible and installation is simple. While these board-type LED conversions are more expensive than the “bulb-type” conversions, the difference is night and day. (Sorry, could not resist.) Two notes: These are polarity sensitive, so please order the correct type for your car. And, because LED’s draw so little power, you will need to replace your flasher unit for your turn signals to work correctly. Order part number 17-1120, which works for either positive or negative ground applications.