Here we have a beautiful and interesting special design, automatic fly back chronograph wristwatch, “Bullhead” called model of Citizen. The wristwatch manifactured by: Citizen Watch Co. Japan, circa 1970's. The Model is: Citizen Chronograph Automatic also known as "Bullhead" and "Challenge Timer". The movement is; in-house with 23 jewels calibre 8110A with hand winding capability. It is a vertical clutch chronograph (beating at 28.800 bph) with column wheel and fly back function. Black date & day wheels, black inner tachymeter ring, case numbers are 4-901177 Y, & 70303958 dial code 901018 K. Case Material: SSB (base metal case, black bezel)&Stainless Steel Case Back and Bracelet. Case width is: 35mm, length is 46mm including crowns and Case depth is 11 mm. The watch is in good condition, as shown in photos. The Watch Fully examined and serviced. Mechanism is working properly. All photos you see above are original and the actual. The postage include no extras. DHL Express worldwide and secure shipping with tracking code. The buyer is responsible for procedures concerning the custom duties, import duties or any extra costs. (if needed)