This listing features a fully original vintage Seiko chronograph from August 1977, model 6139-7100, often affectionately nicknamed “Helmet” due to its unique case shape, which resembles a motorbike or racing helmet. Some collectors also refer to this particular variant with the dark dial as “Darth Vader” for its bold, stealthy aesthetic. These watches were part of Seiko’s golden era of mechanical chronographs, showcasing the brand’s innovation in automatic chronograph development. Key Features & Specifications • Brand: Seiko • Model: Automatic Chronograph “Helmet / Darth Vader” • Reference Number: 6139-7100 • Movement: Seiko 6139A automatic chronograph movement – serviced – Timegrapher results provided • Jewels: 17 • Case Material: Stainless steel • Case Diameter: Approx. 41mm (excluding crown) • Lug Width: 19mm • Dial: Black with sub-dial and tachymeter chapter ring – original • Crystal: Acrylic • Bracelet: Stainless steel bracelet with Seiko clasp, ref. Z050S – original • Functions: Chronograph with 30-minute register, day-date complication with English/Spanish quickset via push • Production Date: June 1977 (serial no: 760843) Condition & Remarks • The watch is in visually striking and fully original condition. • All parts, including the case, crown, pushers, crystal, dial, hands, bracelet, and clasp, are original. • Chronograph resets accurately and functions smoothly. • Pump-style date quickset button works perfectly. • The timekeeping performance is excellent for a vintage watch • Please refer to the Timegrapher image for transparency. • Light surface wear consistent with vintage age; no heavy dents or cracks. • Water resistance not tested or guaranteed due to the vintage nature. • Before use, give the watch a few gentle wrist motions or wind for 1–2 minutes to initialize power reserve. Additional Information • Included: Watch only, as photographed • Shipping: Fast & secure international shipping via FedEx or UPS • Note: Buyer is responsible for any import duties, VAT, customs clearance, or local taxes. • Packing: The item will be carefully packed; photos/videos will be taken before dispatch for transparency and proof of condition. ***No waterproof warranty! This rare Seiko “Helmet” is a collectible piece of horological history, blending robust Japanese engineering with bold 1970s design. A true conversation starter for collectors and vintage chronograph lovers alike.