Line ferrods were also provided in pairs, of which the even numbered one had contacts brought out to the front of the package in lugs suitable for wire wrap so the windings could be strapped for loop start or ground start signaling. The original 1ESS packaging had all the ferrods of an LSF together, and separate from the line switches, while the later 1AESS had each ferrod at the front of the steel box containing its line switch. Odd numbered line equipment could not be made ground start, their ferrods being inaccessible.