Seiko Cal. 6638 - 763

Released in 1985, the Cal. 6638 with design code 763 was part of Seiko's domestic market collection. Powered by the 6638 caliber with 30j jewels beating at 28,800 bph, it delivers a 63 hours power reserve. [seikata-wm-af6e6104df7e]

Also known as: UFO

Specifications

Movement

Kinetic

Case Material

PVD Black

Case Width

46mm

Case Thickness

15.6mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Fixed

Water Resistance

100m

Dial Color

Black

Jewels

30j

Frequency

28,800 bph

Power Reserve

63 hours

Year

1985

Related Models

• Seiko 5265-434
• Seiko 6291-814
• Seiko 7085-905
• Seiko 6345-727
• Seiko 6126-389
• Seiko 6398-202
• Seiko 7110-640
• Seiko 7111-588
• Seiko 6261-661
• Seiko 5295-723
• Seiko 6248-355
• Seiko 4544-365