Seiko Cal. 7138 - 631

The Seiko 7138-631 represents an important milestone in Seiko's 1976 lineup. Powered by the 7138 caliber with 18j jewels beating at 36,000 bph, it delivers a 53 hours power reserve. [seikata-wm-5edb04a8aa7b]

Also known as: Sportsmatic

Specifications

Movement

Hand-Winding

Case Material

PVD Black

Case Width

40mm

Case Thickness

15.4mm

Lug Width

20mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

40m

Dial Color

Green

Jewels

18j

Frequency

36,000 bph

Power Reserve

53 hours

Year

1976

Related Models

• Seiko 4559-441
• Seiko 5617-121
• Seiko 3862-922
• Seiko 0768-179
• Seiko 6256-435
• Seiko 6368-694
• Seiko 0798-625
• Seiko 7166-994
• Seiko 7161-387
• Seiko 4465-191
• Seiko 3821-691
• Seiko 6215-258