1941 Red Army free frank field post letter, Tallinn – Paide

Field post likely from Estonian units incorporated to Soviet Army. Senders address: Tallinn P.O. Box 3 room 4, recruit Vasjugin. Very weak triangular letter cachet “Красноармейское письмо/БЕСПЛАТНО”, with no unit mentioned. With Soviet rates from December 12, 1940 it was possible to send free frank letters to/from Red Army units. Very scarce/rare late item as most ex-Estonian units were already moved to Russia by that time.