Seiko Cal. 6640 - 427

Seiko 6640-427

This Quartz model from 1974 features a 34mm PVD Black case. The Coin-Edge bezel and 34mm case give it a distinctive presence on the wrist. [seikata-wm-394c3fb4a37c]

Also known as: Monster, Baby Tuna

Specifications

Movement
Quartz
Case Material
PVD Black
Case Width
34mm
Case Thickness
12.8mm
Lug Width
22mm
Crystal
Sapphire
Bezel
Coin-Edge
Water Resistance
40m
Dial Color
Silver
Jewels
31j
Frequency
36,000 bph
Power Reserve
49 hours
Year
1974

Related Models

seikata-wm-394c3fb4a37c