It's very similar to the compressed nitrogen cooling gas tank of the Russian 9B238 (9Б238) battery cooling unit (BCU), but not the same.
The 9B238 was introduced with with Russian 9K310 Igla-1 (SA-16 Gimlet) MANPADS (Man-Portable Air Defence System) and is also used with systems up to the 9K333 Verba (SA-29).
The 9B238 has a different internal construction, so it is possible this is from the 9P51 (9П51) BCU of the 9K34 Strela-3 (SA-14 Gremlin), or a different MANPADS based on a Russian design.
Unfortunately I don't have the internal design of the 9P51, but a sectional diagram of the 9B238 is below.
Whatever the model it has the outer casing and other structures, such as the thermal battery, have been removed.
The image above is what is thought to be 9P51 BCU with all coverings present.
The image above is what is thought to be 9P238 BCU with all coverings present.
The image above is a 9B238 BCU with the outer rubber covering (sheath) and other outer structures removed.