The 2S1 Gvozdika is a Soviet 122-mm self-propelled howitzer that resembles the PT-76 but is essentially a version of the MT-LB APC, mounting the 2A18 howitzer. "2S1" is its GRAU designation.In the Russian Army it is commonly known as Gvozdika. 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.