Seiko. A stainless steel automatic calendar chronograph wristwatch Model: Speed-Timer 'Kakume' Reference: 6138-0030 Date: Circa 1976 Movement: 21-jewel Cal.6138B automatic Dial: Blue sunburst, polished baton hour markers with luminous inserts, white outer 1/5 minute divisions, silvered subsidiary dials at 6 and 9 for 30 minute and 12 hour recording, day and date aperture at 3, polished baton hands, orange chronograph hand Case: Brushed and polished tonneau form, screw down back, fixed calibrated bezel with blue tachymetre scale, crown flanked by twin pushers, No.300360 Strap/Bracelet: Steel mesh Buckle/Clasp: Folding clasp Signed: Case, dial & movement Size: 42mm Footnotes: In the 1970s Seiko introduced the reference 6138-0030 Kakume, also known as 'Square Eyes' in Japanese.