Genuine Lucas RB106 12 Volt, 35 Amp, Negative Earth dynamo voltage regulator.
It is easy to fit as a direct replacement for the old, worn mechanical unit.
It has no moving parts so the voltage is accurately controlled and allows charging at lower speeds with no contacts to burn/wear out or stick, avoiding dim lights and bad charging and improving battery life.
It is visually identical to the OE part fitted to many classic vehicles with dynamo systems and screw terminals with the cover held in place by spring clip.
Also known as NCB100 control box, this regulator was fitted to many vehicles, including but not limited to AC, Austin, Bedford, Citroen, Jaguar, Jensen, Lanchester, Land Rover, MG, Morris, Riley, Rover, Singer, Standard, Triumph, Vauxhall and Wolseley models,