The 2S1 Gvozdika (Russian: 2С1 «Гвоздика»; English: carnation) is a Soviet 122-mm self-propelled howitzer that resembles the PT-76 but is essentially a version of the MT-LB APC. "2S1" is its GRAU designation. Alternative Russian designation is SAU-122 but in the Russian Army it is commonly known as Gvozdika ("Carnation"). The 2S1 is fully amphibious with very little preparation, and once afloat is propelled by its tracks. A variety of wider tracks are also available to allow the 2S1 to operate in snow or swamp conditions. It is NBC protected and has infra-red night-vision capability.