This a OE Lucas Relay Jaguar E-Type Cooling Fan 65-71,Field Isolation 65-71,Ignition 65-71,AC Fan Overide 71-74, XJ 69-76 Air Conditioning, MGB Fan 77-80, MGB Battery cut-off 76-80. Cross Reference# 542-235, UKC5146, SRB104, 0-946, 13H153, 33232, UKC5146