Andy, Here is a link to the units I ordered and fitted to my car: https://www.classiccarleds.co.uk/products/led-headlights-h4-fully-integrated-6000-lumen-hi-lo-beam-conversion-9-32v If you search for Caterham on their site, only one set of headlight bulbs will appear in the results... a few other bulbs will also appear in the results but these will be for sidelights and indicators etc... Hope this helps.