The 2S1 Gvozdika is a Soviet self-propelled howitzer introduced in 1972 and in service in Russia and other countries as of 2023. It is based on the MT-LBu multi-purpose chassis, mounting a 122 mm 2A18 howitzer. "2S1" is its GRAU designation. An alternative Russian designation is SAU-122, but 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 track widths are available to allow the 2S1 to operate in snow or swamp conditions. It is NBC protected and has infrared night-vision capability.

The MT-LBu is a Soviet multi-purpose fully amphibious armoured carrier which was developed under the factory index Ob'yekt 10 in the late 1960s, based on the MT-LB. It has a more powerful engine, a 40 cm higher hull and a longer chassis with 7 road wheels on each side.