The successor to the Leopard 1, the Leopard 2, was first produced in 1979. A variety of upgrade programs and options are available for the Leopard 2. The Leopard 2 has had a new smoothbore gun, the 120 millimetre L55 Gun, has been developed by Rheinmetall GmbH of Ratingen, Germany to replace the shorter 120 millimetre L44 smoothbore tankgun on the Leopard 2. It permits effective use of a new APFSDS-T round, DM53 (LKE II), with a longer rod penetrator, and which is under development.