Current collectors for agricultural trailers; Current collectors for industrial trailers; Electric test boxes for testing light circuits on semi-trailers; Electrical connectors for use between a semi-trailer and tractor unit; Electrical control apparatus; Electrical control apparatus being computer operated; Electrical control circuits; Electrical control units for lighting installations; Electrical controls; Electric current sensors; Simulators; Automotive electrical components; Electronic relays; Apparatus for signalling vehicles; Control circuits for use in connection with motor vehicles; Control modules for vehicles and vehicle systems (onboard; Electronic brake controllers for vehicles; Electronic control units for vehicles; Light flashing apparatus for direction indicators of vehicles; On-board computers for vehicles; Voltage regulators for land vehicles; Voltage regulators for vehicles; Wiring looms and harnesses for vehicles (electric cables); Auxiliary relays; Relays, electric; Solid-state component relays; Electronic monitoring apparatus, other than for medical use; Apparatus for monitoring electrical components; Amplification apparatus; Pulse code modulating processors; Pulse code modulation apparatus for transmission via cable; Pulse generators (other than for medical use); Pulse sending devices (other than for medical purposes); Current collectors; Current collectors for caravans; Current collectors for carriages; Electric resistors; Force sensing resistors; Inductive resistors; Resistor networks; Trimmer resistors; Variable resistors; Electrical resistors; Resistors