The PT-91 Twardy is a Polish main battle tank. A development of the T-72M1, it entered service in 1995. The PT-91 was designed at the OBRUM and is produced by the Bumar Łabędy company, part of the Bumar Group, a Polish technical military consortium. Changes from the T-72M include a new dual-axis stabilized fire-control system, reactive armour, a more powerful engine, transmission and new automatic loader.

The T-72 is a family of Soviet main battle tanks that entered production in 1969. The T-72 was a development based on the T-64 using thought and design of the previous Object 167M. About 25,000 T-72 tanks have been built, and refurbishment has enabled many to remain in service for decades. It has been widely exported and has seen service in 40 countries and in numerous conflicts. The Russian T-90 introduced in 1992 and the Chinese Type 99 are further developments of the T-72. Production and development of various modernized T-72 models continues today.