Most older British cars did not come equipped with headlamp relays. The advantage of a relay is that much more current gets to the lamps, meaning much brighter lighting, as well as a greatly reduced current draw through the lighting switch, so the switch will last a lot longer. We strongly recommend this kit for any British car built before about 1980. It comes complete with two relays, inline fuse, correct color code wires, and instructions for installation.
Be safe and be seen!