The present invention provides for an electronic isolator, or barrier, device arranged for receiving field wiring from a field element and further including connection means arranged to receive a surge element for providing surge functionality to the device, and to provide surge protection to the connectivity by way of the field wiring, the device arranged such that the surge element connects to the device and to the said field wiring by way of the said connection means so that operational connection/disconnection of the surge element to the device does not require disconnection of the field wiring from the device.