USSR. Cover of registered letter sent from Leningrad on April 07, 1924. "Narrow frame".

Cover of registered letter sent from Leningrad to Brussels (Belgium) on April 07, 1924. It is made from white paper, size 122-97 millimeters. Cover is franked with: four stamps 6 k., in memory of Lenin, size 20,5-25 millimeters, on the front side of the envelope; four stamps - 3 k., size 20,5-25 millimeters; standard stamp 4 k. Strip of four stamps 3 k. "narrow frame" occurs very rarely on the envelope. With certificate of Frenkel Dmitry.