The KB Tochmash / Nudelman S-25L series are large calibre tube launched 400 kg folding fin rockets, with terminal guidance seekers to provide a precision weapon for close air support and battlefield interdiction operations.
The basic unguided S-25 rocket is designed to self stabilise by rotating about its axis at 600 RPM, using canted tail fins to impart the rotation. This weapon achieved IOC with the FA-VVS in 1979. A 150 kg penetrator warhead is used with a 21 kg shaped charge precursor warhead.
The guided variants retain this arrangement, with the seeker section on the nose attached the weapon fuselage by a low friction bearing, decoupling the seeker from the fuselage rotation.
Two basic variants exist, the S-25L and improved S-25LD, both with the KBT 24N1 gimballed semiactive laser homing seeker used in a number of other weapons.
KBT have also adapted other seeker hardware and developed an infrared homing seeker variant, the S-25IRS, and a television seeker equipped variant, the S-25TV. Phazotron have also offered an active radar homing seeker for the weapon. source: ausairpower.net