ROLEX gents wristwatch Oyster Perpetual Cosmograph Daytona, self winding, reference 16520, N-series, LC 100, superlative chronometer officially certified in stainless steel including oyster bracelet, screwed down case back, winding crown & pusher, original dial later, display of hours, minutes, constant second at 9 & chronograph, bezel with engraved tachometer graduation till 400 Units per Hour, sapphire crystal, rhodium plated movement, calibre 4030, 31 jewels, monometallic balance, Breguet- hairspring,central rotor, adjusted in 5 positions, diameter approx. 40 mm, length approx. 22 cm, original certificate & Booklet, sold in May 1993, signs of use due to age, condition 2, discontinued model