The 2S7 Pion ("peony") or Malka is a Soviet self-propelled gun. "2S7" is its GRAU designation. It was identified for the first time in 1975 in the Soviet Army and so was called M-1975 by NATO (the 2S4 Tyulpan also received the M-1975 designation), whereas its official designation is SO-203 (2S7). Its design is based on a T-80 chassis carrying an externally mounted 2A44 203 mm gun on the hull rear.