The Tetrarch is a Soviet tier 2 premium light tank. It is currently not available from the in-game store.
Developed in 1936 by the Vickers-Armstrong company, with a total of 177 vehicles in two basic modifications the Tetrarch Mk I and the Tetrarch Mk ICS manufactured from 1941 through 1942. In 1942 twenty vehicles were delivered to the USSR under Lend-Lease, of which 19 fought on the Eastern Front until October 1943.
The in-game Tetrarch is one that was provided to the USSR from Britain through the Lend-Lease Act. It was available as a 2012 New Years gift from Wargaming to all players for a limited time with the release of the 0.7.1 patch. The Tetrarch has also appeared in gift shop bundles on rare occasions. It is well-armed with a excellent gun, fast on firm ground and has a powerful radio. This is balanced by very weak armor, poor view range, and sluggish cross country and traverse performance.
MkVII Tetrarch - A World War II air transportable British light tank. Developed by Vickers between 1938-1940 on its own initiative, initially as a reconnaissance tank, to replace the obsolete Mk VI. However, because of poor results shown by light tanks in the first year of World War II, the production of the Tetrarch, which began in 1940, was soon stopped. Interest in the Mk VII began again in 1941 when it was decided to use it as an air transportable tank. Series production of the Tetrarch was resumed and continued from 1941 to 1942. Total production amounted to 177 vehicles. The Tetrarch saw limited use by British troops in battle during the years 1942-1945 and remained in service after the war until the end of the 1940s. The MkVII was also available in the USSR in small quantities during the war under the Lend-Lease program.
Sources and External Links
Historical info paraphrased from a Google Translate version of the RU WoT Wiki entry on the MkVII.