This is a vintage Jager LeCoultre tank type rectangular watch, featuring a 14k or 18k yellow gold (depending on being American or English) case and a manual-winding movement.
This timepiece originates from the 1940s or 1950s and has Art Deco design elements, such as stepped lugs.
Similar models have been valued between £1,400 and £4,500 depending on the specific metal, condition, and presence of original packaging.
