Thomas' Timepieces - Seiko 6138-3000 and 6138-3002, both models often referred to as the Seiko Jumbo. The Seiko 6138 was arguably the world's first automatic chronograph (Zenith/Movado El Primo also claimed to
![NOS SEIKO JUMBO Vintage automatic chronograph watch Ref. 6138-3002 Cal. 6138 + BOX *** NEW OLD STOCK *** Seiko Vintage watches - Watches83 NOS SEIKO JUMBO Vintage automatic chronograph watch Ref. 6138-3002 Cal. 6138 + BOX *** NEW OLD STOCK *** Seiko Vintage watches - Watches83](https://watches83.com/56634-thickbox_default/nos-seiko-jumbo-vintage-automatic-chronograph-watch-ref-6138-3002-cal-6138-box-new-old-stock-.jpg)
NOS SEIKO JUMBO Vintage automatic chronograph watch Ref. 6138-3002 Cal. 6138 + BOX *** NEW OLD STOCK *** Seiko Vintage watches - Watches83
![Vintage Seiko Jumbo Chronograph ref. 6138-3002 – 1975, Serviced, Original Bracelet - ChronoTimepieces Vintage Seiko Jumbo Chronograph ref. 6138-3002 – 1975, Serviced, Original Bracelet - ChronoTimepieces](https://chronotimepieces.com/ctsitecms/wp-content/uploads/Seiko-Chronograph-Jumbo-ref.-6138-3002.jpg)