Two polarised relays 4500/4500 used on 4-button selective omnibus circuits, Newport station exchange Two polarised relays 4500/4500 used on 4-button selective omnibus circuits
Two polarised relays used on D.C. selective ringing telephone omnibus circuit, Newport station exchange Two polarised relays used on D.C. selective ringing telephone omnibus circuit
Two polarised relays 10000/10000: (a) used on railway control telephone system; (b) used on railway selective circuits - from Newport station exchange Two polarised relays 10000/10000