This MiG-25RBK that was rolled out in May 1978, was an upgraded version equipped with a <em>Kub-3M</em> ELINT suite and a 
SPO-15 <em>Bereza</em> RHAWR, of which some antennas were situated on the side of the reactors air intakes.
It was subsequently further upgraded to RBF standards - see the MiG-25RBF folder.