The 2K12 Kub, exported as Kvadrat and known to NATO as SA-6 Gainful, is a Soviet tracked medium-range surface-to-air missile system built around 3M9 missiles, 2P25 launch vehicles, and the 1S91 Straight Flush radar. Its conflict record spans the 1973 Yom Kippur War, where Egyptian and Syrian SA-6 batteries became a central air-defense problem for Israeli aviation, and later legacy use or transfer in Ukraine, Syria, Nagorno-Karabakh, Libya, and Yemen.
Egyptian and Syrian forces fielded Kub/SA-6 batteries during the October 1973 Yom Kippur War, where the system formed part of a dense ground-based air-defense network and was credited in museum and air-power studies with shooting down Israeli aircraft and complicating Israeli suppression efforts.
Ukraine received additional Kub/Kvadrat-family air-defense equipment during the full-scale phase of the Russia-Ukraine War: Slovak reporting listed Kub launchers, a Kub radar station, and 3M9 missiles; SIPRI records Czech and Polish second-hand Kvadrat system deliveries and Czech, Polish, and Slovak 3M9 missile transfers for Kvadrat; Ukrainian reporting in 2026 described adapted Kub systems on combat duty against Russian Shahed-type attack drones.
Role detailsSyrian government air-defense forces were reported by Russia and international coverage as deploying 2K12 Kub/Kvadrat systems while responding to the 14 April 2018 U.S., British, and French missile strikes; the claimed interception results remained disputed by U.S. and independent assessments.
Role detailsArmenian and Artsakh forces fielded Soviet-era 2K12 Kub/SA-6 systems as part of their air-defense network during the 2020 Nagorno-Karabakh war; open-source loss documentation recorded 1S91 radar vehicles destroyed by Azerbaijani TB2s and loitering munitions, plus one captured 1S91 component.
Misrata-linked reporting during the 2014 Second Libyan Civil War showed a 2K12 Kub/SA-6 launcher fitted to an EE-11 Urutu in Misrata and described the local modification as likely intended for direct fire; Liveuamap reporting separately said Misrata Air College deployed 2K12 Kub/SA-6 Gainful to protect Misrata Airbase.
Houthi-aligned forces used an SA-6/Kub-family surface-to-air missile in June 2019 to shoot down a U.S. MQ-9 over Yemen, according to U.S. Central Command; CSIS identifies the related Houthi Fater-1 display as a 3M9/SA-6-derived missile tied to Yemen's earlier Kub/Kvadrat inventory.
Role detailsThe Kub family is best understood as a battery-level air-defense system: the 1S91 Straight Flush/SURN radar vehicle searches, tracks, illuminates, and guides; the 2P25 launch vehicles carry the ready 3M9 missiles; and transport vehicles handle reloads. Later modernization programs focused less on the basic tracked layout and more on radar electronics, command links, optical channels, identification equipment, and missile compatibility.
Czech MoD data describes one 1S91 radar vehicle, four launchers, and two transport/supply vehicles, with two missiles assignable against one target.
The system uses radar search, tracking, illumination, and missile guidance, with a television optical channel documented for jamming-resistant operation.
RETIA modernization material describes upgraded SURN radar/control vehicles, 2P25 launcher integration, new electronics, NATO-compatible command links, and missile-replacement options.
Sources: 2K12 M2 KUB - NATO code: SA-6 GAINFUL; 2K12 Kub; SURN CZ modernization of 2K12 KUB.
Kub/Kvadrat variant names usually describe system-level modernization or export configurations. The 3M9 missile, 2P25 launcher, and 1S91 Straight Flush/SURN radar are component records rather than same-family variants of the parent system.
| Variant | Configuration | Designation notes |
|---|---|---|
| 2K12 Kub | Baseline Soviet system | Open technical references place the original Kub system in service in 1967 with the 3M9 missile, 2P25 launch vehicle, and 1S91 radar/control vehicle. Sources: 2K12 Kub, SA-6 Gainful - GlobalSecurity |
| 2K12E Kvadrat | Export configuration | WeaponSystems.net and GlobalSecurity identify Kvadrat as the export designation used for Kub-family systems supplied outside the Soviet Union. Sources: 2K12 Kub, SA-6 Gainful - GlobalSecurity |
| 2K12M1 Kub-M1 | Early modernization | GlobalSecurity lists Kub-M1 as a 1973 modernization step in the Kub family. Sources: SA-6 Gainful - GlobalSecurity |
| 2K12M2 Kub-M2 | Documented service designation | The Czech Ministry of Defence data sheet identifies its system as 2K12 M2 KUB and gives official figures for the missile, radar, launcher, and battery arrangement. |
| 2K12M3 Kub-M3 | Later Soviet modernization | GlobalSecurity lists Kub-M3 as a 1976 modernization, and the National Defence University of Ukraine describes a Kub-M3 exhibit with updated range, altitude, and reaction-time figures. Sources: SA-6 Gainful - GlobalSecurity, Kub-M3 - National Defence University of Ukraine |
| 2K12M4 Kub-M4 | Kub/Buk transition configuration | GlobalSecurity describes Kub-M4 as a 1978 step connected with the early Buk system rather than as a separate cataloged weapon page here. Sources: SA-6 Gainful - GlobalSecurity |
Kub batteries use the 3M9 missile family as the ready missiles carried on the tracked launch vehicles.
| Carried item | Item type | Carriage evidence |
|---|---|---|
 | Surface-to-air missile | Weaponsystems.net identifies the 3M9 as the Kub missile and describes each 2P25 launch vehicle as carrying three ready missiles. Sources: 2K12 Kub |
The parent Kub system combines radar/control equipment with tracked firing vehicles rather than operating as a single self-contained launcher.
| Compatible item | Item type | Compatibility evidence |
|---|---|---|
| Tracked launch vehicle | Weaponsystems.net describes the 2P25 as the Kub launch vehicle, while RETIA modernization material identifies 2P25/SPU launchers as part of the Kub firing chain alongside the SURN radar vehicle. Sources: 2K12 Kub, SURN CZ modernization of 2K12 KUB |
Open technical references place Kub development in the 1958 to mid-1960s period as a mobile medium-range air-defense system for Soviet ground forces.
Sources: 2K12 Kub
WeaponSystems.net and GlobalSecurity place the original Kub system in service in 1967 with 3M9 missiles and tracked launch vehicles.
Sources: 2K12 Kub, SA-6 Gainful - GlobalSecurity
The Polish Aviation Museum identifies the Yom Kippur War as the Kub combat debut, while GlobalSecurity lists Kub-M1 as a 1973 modernization step.
Sources: 1S91M1-2 SURN station - Polish Aviation Museum, SA-6 Gainful - GlobalSecurity
GlobalSecurity and the National Defence University of Ukraine identify Kub-M3 as a later 1970s modernization with different range, altitude, and reaction-time figures from earlier Kub data.
Sources: SA-6 Gainful - GlobalSecurity, Kub-M3 - National Defence University of Ukraine
GlobalSecurity describes Kub-M4 as a 1978 configuration connected with the emerging 9K37 Buk family.
Sources: SA-6 Gainful - GlobalSecurity
Slovakia approved Kub launchers, a Kub radar station, and 3M9 missiles for Ukraine; Czech reporting said Prague was supplying two 2K12 Kub systems with missiles, and SIPRI records second-hand Kvadrat systems and 3M9 missile transfers to Ukraine from Czechia, Poland, and Slovakia.
Sources: Vláda rozhodla: Slovensko daruje stíhačky MiG-29 Ukrajine, Czech Republic supplies Ukraine with two Kub air defence systems, SIPRI Arms Transfers Database - Ukraine Kvadrat and 3M9 transfers
