Sirena

An series of Soviet and Russian radar warning receivers, devices with Serena designations first were reported on the [MiG-21 (fighter)]] (Western: MiG-21 FISHBED.

Other variants, including one with no blind spots, have been described on the MiG-25 (fighter) and reconnaissance aircraft (Western: MiG-25 FOXBAT. Another was on the Yak-28 (bomber) (Western: Yak-28 BREWER) electronic warfare variant.

The SPO-15LE SIRENA is on the Su-22 (fighter) (Western: Su-22 FITTER]]), an upgrade of the Su-17.