Sea Zenith is an advanced four-barrelled 25 mm CIWS used by the Turkish Navy on their MEKO 200 frigates, like the Barbaros and Yavuz classes. It was developed in the 1980s by Oerlikon Contraves (Rheinmetall Air Defence since 2009) around their KBB gun and manufactured in Switzerland. This automatic gun uses a 25x184mm cartridge (longer than the one used by the more common KBA gun) at a rate of 800 rounds a minute. Using four independent guns instead of one multi-barrelled Gatling gun improves reliability. The system is mounted in an enclosed automatic turret and directed by the Seaguard radar developed by Contraves. The turret is tilted back to allow a higher elevation to intercept diving missiles. The system's primary purpose is defence against anti-ship missiles, and other precision guid