supply of relay ac immune, plug-in type style qspa1, dc neutral line slow to pick up 24v dc 8f/4b contacts, front and back contacts metal to carbon complete with plug board, retaining clip and copper annealed connectors conforming to brs;933a,irs;s-60,irs;s-60,irs;s-34,irs:23 (as applicable).interlocking code: abdej.