SORNA Chrono unusual chronograph with world time display so called Bullhead, Switzerland around 1970, manual winding, chrome-plated case, screwed down stainless steel case back, to coordinate by 2 revolving inner rings & crowns outside 2 & 4, multi coloured dial, 15 minutes register, date at 12, 17 jewels, calibre EB8420, measures approx. 45 x 45 mm, condition 2