According to Wikipedia: "The Long March 3C (simplified Chinese: Changzheng Sanhao Bing Huojian), also known as the Changzheng 3C, CZ-3C and LM-3C, is a Chinese orbital carrier rocket. It is launched from Launch Complex 2 at the Xichang Satellite Launch Centre. A 3-stage rocket with two strapon liquid rocket boosters, it is a member of the Long March 3 rocket family, and was derived from the Long March 3B. It was designed to fill a gap in payload capacities between the Long March 3A and 3B."