The Dong Feng 4 (Chinese: 东风4, meaning "East Wind") or DF-4 (also known as the CSS-3) is a two-stage Chinese Intercontinental ballistic missile with liquid fuel (Nitric acid/Unsymmetrical dimethylhydrazine). It was thought to be deployed in limited numbers in underground silos beginning in the 1970s and early 1980s. The Dong Feng 4 has a takeoff thrust of 1,224.00 kN, a takeoff weight of 82000 kg, a diameter of 2.25 m, a length of 28.05 m and a fin span of 2.74 m.