GOLD ZENITH WITH CHRONOGRAPH, 50S Three body tonneau 18K gold case, n. 592773, concave lugs, sloped bezel, snap on back, rectangular pushers. Not original strap and buckle.
Silvered dial signed, applied star, applied bâton indexes, Arabic 12 and 6 numerals, minute and 1/5th second divisions, outer tachymetric scale, subsidiary seconds dial and 45-min register. Gilt dauphine hands. 
Signed manual winding movement, rhodium-plated caliber 156, column-wheel system for the chronograph, lever escapement, monometallic balance with screws, Breguet hairspring.
Diameter Ø: 37,5 mm | Weight: 37,8 g
Note: working.