Seiko Cal. 5638 - 646

The Seiko 5638-646 represents an important milestone in Seiko's 1988 lineup. Powered by the 5638 caliber with 34j jewels beating at 28,800 bph, it delivers a 64 hours power reserve. [seikata-wm-cdab00b0a1d5]

Also known as: Crown, Baby Tuna

Specifications

Movement

Quartz

Case Material

Titanium

Case Width

35mm

Case Thickness

10.9mm

Lug Width

21mm

Crystal

Mineral

Bezel

Bidirectional

Water Resistance

170m

Dial Color

Cream

Jewels

34j

Frequency

28,800 bph

Power Reserve

64 hours

Year

1988

Related Models

• Seiko 7168-571
• Seiko 6641-511
• Seiko 5262-225
• Seiko 7116-171
• Seiko 6160-365
• Seiko 5246-298
• Seiko 6155-162
• Seiko 5675-851
• Seiko 4511-832
• Seiko 4440-751
• Seiko 3823-486
• Seiko 5685-643