also known as the Lemania 7500, 42.9mm, 15 jewels, winds from the stem
similar movement was the 401 (Lemania 7000) with different winding mechanism
Other versions were key wound, 390 and 400 (Lemania 7520 and 7020)
All date from 1947 and were produced in 1500 pieces or less as Omega Calibres