波蘭主戰坦克，搭載雙軸穩定火控系統，反應裝甲，自動裝彈機，PT-91主戰坦克

PT-91 「堅韌」型坦克（波蘭語：Twardy）是一種波蘭制主戰坦克。它是T-72M1型主戰坦克的改進型，最早於1995年服役。PT-91是由OBRUM（OBRUM是波蘭語Ośrodek Badawczo-Rozwojowy Urządzeń Mechanicznych的縮寫，意為機械設備研發中心），並由Bumar Łabędy公司生產，後者是波蘭軍事財團Bumar Group的一部分。相比T-72，PT-91加裝了一套新型雙軸穩定火控系統、反應裝甲、一台動力更強的發動機、傳動系統和新型自動裝彈機。與其他許多T-72改進型不同，波蘭陸軍的PT-91在升級中所使用的部件幾乎全部是本國企業製造的（包括新型發動機、火控系統和所有通信系統組件）。這些部件中有許多都被用於為其他國家升級其現有的T-72坦克，比如捷克的T-72M4Cz、喬治亞的T-72SIM-1和印度的T-72 Ajeya Mk2。
The PT-91 Twardy (Polish pronunciation: [ˈtfar.dɨ], English: Tough) is a Polish main battle tank. A development of the T-72M1, it first entered service in 1995. The PT-91 was designed at the OBRUM (OBRUM for Ośrodek Badawczo-Rozwojowy Urządzeń Mechanicznych – Polish for Research and Development Centre for Mechanical Appliances) and is produced by the Bumar Łabędy company, a part of the Bumar Group, a Polish technical military consortium. Changes from the T-72 include a new dual-axis stabilized fire-control system, reactive armour, a more powerful engine, transmission and new automatic loader.Unlike many other T-72 upgrades, the Polish Army PT-91s are upgraded using elements created almost exclusively by domestic companies, including a new engine, the fire control system and all communication system elements. Many of those elements were used to upgrade existing fleets of T-72 tanks in countries including the Czech Republic (T-72M4 CZ), Georgia (T-72SIM-1), and India (T-72 Ajeya Mk. 2). A total of 232 PT-91 tanks were delivered to the Polish Land Forces: 92 newly built vehicles and 140 from refurbished T-72A and T-72M1 tanks designated PT-91M1 and PT-91MA1, respectively.