Hydraulic brake light switch suitable for TR3 - 4. This switch has the correct UNF thread for the original 5-way union as fitted on TR3's from TS13469 up to end of production on the TR4. Both TR3 & most 3A's were fitted with screw type electrical connectors on the switch, unfortunately these are no longer available. However the wiring can be easily modified to suit the Lucar connectors. 1 required per car.