Seiko Cal. 6643 - 256

The 6643-256 is a sought-after Quartz piece from Seiko's golden era. Powered by the 6643 caliber with 17j jewels beating at 36,000 bph, it delivers a 59 hours power reserve. [seikata-wm-3982bb726c1d]

Also known as: Sumo, Navigator

Specifications

Movement

Quartz

Case Material

PVD Black

Case Width

45mm

Case Thickness

9.3mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

50m

Dial Color

Silver

Jewels

17j

Frequency

36,000 bph

Power Reserve

59 hours

Year

1973

Related Models

• Seiko 6689-496
• Seiko 3815-209
• Seiko 6113-587
• Seiko 3847-557
• Seiko 4428-588
• Seiko 6389-639
• Seiko 6646-294
• Seiko 3835-478
• Seiko 5639-377
• Seiko 6186-156
• Seiko 5210-557
• Seiko 6695-962