AKA: 9K31M;9M31M;Gaskin;SA-9B;Strela-1M. Status: Operational 1970. Payload: 3.00 kg (6.60 lb).
In 1968-1970 a modernised version of the Strela was developed, which included additional equipment to locate targets. The Leningrad Production Establishment Vektor Minpromsoyuz provided a passive radio detection-finder, linked to the optical sight. The 9M31 missile was improved to increase range of the missile, the kill radius of its warhead, the minimum altitude at which a target could be intercepted, and improved accuracy. State trials of the Strela-1M were conducted in May-July 1969, and accepted for use by the surface forces in December 1970.
The vehicle-mounted version of the system consists of: