Vintage Soviet Mechanical Watch "Raketa Gayka / Nut" with Rare Top Calendar 

Up for sale is a highly collectible and iconic Soviet timepiece — **Raketa "Gayka" (Nut / Hexagon)**, manufactured by the legendary Petrodvorets Watch Factory (PCHZ) in the USSR during the 1980s. This model is exceptionally popular among vintage watch enthusiasts due to its unique geometric case and unusual calendar complication.