ROLEX Oyster Ultra Prima early wristwatch so called 'channel swimmers', Switzerland around 1930, manual winding, octagonal nickel case reference 2136, screwed down bezel & stainless steel case-back, original screwed down winding crown, silvered dial restored, constant second at 6, blued steel hands partial replaced, silvered movement, 15 jewels, screw balance with Breguet-hairspring, measures approx. 35 x 32 mm, needs to be overhauled, condition 3