British A13 in use by German forces (G = Guderian ? ) and knocked out in in Russia. Long way from home but I assume captured in North Africa in early desert battle and sent to Russia.

A 13 cruiser tank

Soviet-built BT-5 medium tank, converted to German service, destroyed in Russia, 1941.  The "G" mark visible on its rear indicates "Guderian";  indicating membership of Panzergruppe II/2nd Panzer Army (1941).  

The BT series was one of the most important Soviet tank series.  The BT-5, in particular, served from the Spanish Civil War all the way through to the Soviets' end-war campaign against the Japanese.  The four-roadwheel Christie suspension, visible here, reflects the fact that the BT series was developed from the revolutionary (but unsuccessful in its home country) Christie M31 tank, which was, not so much licensed, as pirated by the Soviet Union.  An important contribution of the BT basic design to the design of the five-roadwheel Christie T-34.  The sloped glacis plate, retained by the BT series from the Christie, may also have influenced the decision to apply sloped armour on a simple, consistent basis to the T-34.  Best regards, JR.