The Belarusian Precision Electro-Mechanics Plant is developing an extended range multiple rocket launcher (MRL) under Polonez family, according to the statement of an official spokesperson for the State Military Industry Committee (GKVP) made at MILEX 2017. Designated as B-300, the MRL has a firing range of up to 300 km. The plant also unveiled B-200 Polonez MRL system, consisting of B-200BM combat vehicle, B-200TZM transporter-loader vehicle, and B-200BMU mobile command-and-control (C2) post vehicle, at MILEX 2017. Armed with eight ready-to-launch 301 mm missiles, B-200 MRL has been delivered to Belarusian armed forces in 2016.