This wire set is made specifically for all "W" series Tractors (WC,WD,WF,WD45) equipped with Distributor. Made specifically for the 201 & 226 engines that came in the "W" series Tractors. All wires are numbered & cut to length per cylinder. Used with Distributor fired ignitions.    Can be used with Electronic Ignition!  Quality 7mm Spark Plug wire.