The S-75 is a Soviet-designed, high-altitude air defence system. It is built around a surface-to-air missile with command guidance. Following its first deployment in 1957 it became one of the most widely deployed air defence systems in history. It was produced in the People's Republic of China under the names HQ-1 and HQ-2. Egyptian engineers produced a reverse-engineered S-75 with the name Tayir-as-Sabah.