ZENITH EL PRIMERO. A BI-COLOR STAINLESS STEEL AND YELLOW GOLD GENTS AUTOMATIC CHRONOGRAPH. Model: El Primero, Rainbow. Case Reference Number: 53-0360-400. Date: c.1990's. Movement: Singed, automatic. Dial: Signed, white, gilt applied batons, gilt sword hands, subsidiary dial at the 3,6 and 9 o'clock position for chronograph, date aperture between  4 and 5 o'clock position. Case: Signed, stainless steel, 18K yellow gold Tachymeter, screw down back. Bracelet: Signed, stainless steel and yellow gold. Size: 40mm.