ZENITH REF. SP 1205 EL PRIMERO CHRONO STEEL
Zenith, "Chronograph, Automatic, El Primero," case No. 861D772,
Ref. SP 1205. Made in the 1970s.
Fine and rare, self-winding, water-resistant, stainless steel
wristwatch with round button chronograph, registers, date and
tachometer.
Two-body, polished and brushed, flat bezel, lapidated lugs,
screwed-down case back.
Two-tone silver and black with applied steel luminous baton
indexes, subsidiary dials for the seconds, 30-minute and-12
hour registers, outer 1/5th seconds track and tachometer scale,
aperture for the date between 4 and 5. Luminous white and
black baton hands, red luminous seconds register.
Cal. 3019 PHC, rhodium-plated, 31 jewels, straight-line
lever escapement, monometallic balance, shock absorber,
self-compensating flat balance spring, index regulator.