Hamilton 60

Vintage Swiss-made manual-wind movement produced in the 1960s-1970s, based on ETA 2390. Measures 10.5 lignes (27mm) diameter. Part of Hamilton's transition era after acquiring Buren Watch Company in 1966. The caliber 60 was followed by the slightly larger caliber 61 (11.5 lignes) and caliber 62 (61 with calendar complication). Features flat hairspring and 52-degree lift angle.