tender for relay qnna1 (6f/2b), ac immune, plug in type, style qnna1, twin dc neutral line, 24v, 6f/2bcontacts each for lh and rh, front and back contacts metal to carbon, complete with plug board, retaining clip &connectors conforming to brs:960, irs:s 60, irs:s:34 & irs:23 (as applicable). the interlocking code for thisunit shall be cdehx.