Seiko Cal. 5278 - 637

The 5278-637 is a sought-after Quartz piece from Seiko's golden era. Powered by the 5278 caliber with 33j jewels beating at 28,800 bph, it delivers a 43 hours power reserve. [seikata-wm-790c308484a2]

Also known as: Tuna, Sportsmatic

Specifications

Movement

Quartz

Case Material

Two-Tone

Case Width

37mm

Case Thickness

11.4mm

Lug Width

22mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

120m

Dial Color

Blue Sunburst

Jewels

33j

Frequency

28,800 bph

Power Reserve

43 hours

Year

1978

Related Models

• Seiko 5220-108
• Seiko 0710-797
• Seiko 6233-500
• Seiko 4521-287
• Seiko 0776-321
• Seiko 6145-776
• Seiko 4477-585
• Seiko 7166-632
• Seiko 6276-742
• Seiko 5224-159
• Seiko 6233-464
• Seiko 6199-329