Probably only useful in a very small skirmish. Ammunition not included.
(Update: I have just been advised by an ex Tank Commander and Cufflink Aficionado that these are the world famous "T34 Soviet Tanks". Who'da guessed?)
Dimensions: 25mm x 12mm (approx.) - measurement excludes gun barrel. With gun barrel is approx. 29mm. Weight per cufflink: approx. 16g (heavy)
Size = x mm (W x H)