Overview Up for auction is an iconic and highly collectible vintage Citizen Challenge Timer "Bullhead" Automatic Chronograph (Ref. 67-9011). Celebrated for its distinct crown-and-pusher configuration at the top of the case (resembling a bull's horns), this timepiece is a masterpiece of 1970s Japanese watchmaking engineering. Featuring the legendary in-house Caliber 8110A automatic movement with a Flyback function, this model remains one of the most sought-after vintage Japanese chronographs on the market. Specifications & Details Brand: Citizen Model: Challenge Timer "Bullhead" Chronograph Reference Number: 67-9011 Case Number / Serial: 4-901177 K / 70302027 Gender: Men / Unisex Period: 1970s (Circa 1977) Movement: Citizen In-House Caliber 8110A Automatic (23 Jewels, High-Beat 28,800 bph, Flyback Chronograph, Hand-winding capable) Case Material: Stainless Steel / Base Metal Top (Polished) Case Width: Approx. 38 mm (excluding crown and pushers) Dial: Gold / Yellow sunburst dial with black subdials (Panda style), vertical Day-Date display at 6 o'clock, and tachymeter inner bezel Crystal: Mineral Glass Crown/Pushers: Original "Bullhead" layout (located at the 12 o'clock position) Bracelet Material: Stainless Steel with original signed Citizen folding clasp Wrist Size / Total Length: Fits up to an 18 cm