"K" for Krylataya ("Winged").
Variant intended to carry various types of cruise missiles.
At present, it includes:
9M728 (SSC-X-7) also known as R-500 – flight altitude up to 6 km, published range up to 500 km although it may be higher and automatic adjustment in the way, follow of terrain relief in flight.
The missile is evolved from 3M10, 3M54/3M14 and Kh-101/102 missiles and can be launched also by the Iskander-M.
9M729 (SSC-X-8) – new long-range missile that is reportedly land-based version of the 3M14 Caliber-NK missile complex with a range between 300–3,400 miles (480–5,470 km) and may be based even on the air-launched Kh-101 cruise missile with a range over 5,500 kilometres (3,400 mi).
According to RF, its range is only 480 km and its specially-developed self-propelled launcher can carry 4 missiles.
The 9M729 missile has a higher yield warhead and a new control system for greater accuracy.
Most parts and components of the 9M728 and 9M729 missiles are identical.

Currently there are 7 different types of ballistic and cruise missiles for both variants of the Iskander missile system.
"K" for Krylataya ("Winged"). Variant intended to carry various types of cruise missiles. At present, it includes:
9M728 (SSC-X-7) also known as R-500 – flight altitude up to 6 km, published range up to 500 km although it may be higher and automatic adjustment in the way, follow of terrain relief in flight. The missile is evolved from 3M10, 3M54/3M14 and Kh-101/102 missiles and can be launched also by the Iskander-M.
9M729 (SSC-X-8) – new long-range missile that is reportedly land-based version of the 3M14 Caliber-NK missile complex with a range between 300–3,400 miles (480–5,470 km) and may be based even on the air-launched Kh-101 cruise missile with a range over 5,500 kilometres (3,400 mi). According to RF, its range is only 480 km and its specially-developed self-propelled launcher can carry 4 missiles. The 9M729 missile has a higher yield warhead and a new control system for greater accuracy. Most parts and components of the 9M728 and 9M729 missiles are identical.
Currently there are 7 different types of ballistic and cruise missiles for both variants of the Iskander missile system.
9K720 Iskander