Varistors

A protection device for incorporation into an electrical connector (500), the protection device comprising a varistor plate (514) having first and second faces and having:

• a first through-going aperture for receiving a live (502) or neutral (504) pin of the electrical connector (500) and a first conductive layer on the first face of the varistor plate for electrically connecting the first face of the varistor plate to the live (502) or neutral (504) pin;
• a second through-going aperture for receiving a ground pin of the electrical connector and a second conductive layer on the second face of the varistor plate for electrically connecting the second face of the varistor plate to the ground pin (506), wherein at least one of the first conductive layer or the second conductive layer comprises a metal surface coating layer deposited onto the varistor plate (514),
• so that in use, and in response to an excessive voltage across the live (502) or neutral pin (504) and the ground pin (506), the varistor plate (514) will conduct electricity from the live (502) or neutral (504) pin to the ground (506) pin.