This Cigar lighter lead is a curly cable which allows all vehicle servers to be powered from the vehicle's cigar/cigarette lighter socket or if used in conjuntion with the battery clip power lead adaptor to obtain power direct from the battery. This is useful in the case that the diagnostic lead / socket in use does not supply a power feed.
It should be noted that the cigar/cigarette socket supply may be supplied via the ignition switch, but if this is not connected or does not work for any other reason then a using the battery clip adaptor with the Cigar lighter lead allows a direct connection. It also adds approximately 1.5meters of cable.