They are fitted into the indicator wires near each bulb - the problem with LEDs is they use so little watts that the flasher unit think because of the lack of resistance that a bulb (s) is faulty. The ones I saw on ebay are supplied with scotchlock connectors which I suppose are adequate. I use spring lever connectors on my mh wiring - done a lot of internal led's - (Toolstation part no 65246). You just lift the levers, push in your bared cables and push shut. Very secure but if they are never to be disturbed again then some extra insulating tape wouldn't go amiss. £2.87 for 10 pack, although you only need 4 obviously. Or use the scotchlocks. Bob.