This "Pigtail" wire is all that carries current through the distributor to the points.Fits 23 and 25d type distributors. Low Tension Lead for cars with Lucas Distributors. Austin Healey BJ7 from (e)29F-H3563, BJ8, Jaguar E-Type, XJ6 to 1979, MGA, MGB 1963 to 1974, Midget 948 to 1275, Triumph TR2, TR3, TR4, TR4A, GT6 and TR6. With use the wire on the low tension lead will become brittle and break and the car will stop, not good for you on your drive. Every time you change the distributor cap or rotor you will need to check low tension lead