Side by side

Lum-Tec B66 Day DatevsSeiko Prospex Sea The Black Series

The numbers, the dial colors, the calibers — laid out so you can stop flipping between tabs.

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B66 Day Date
Lum-TecB66 Day Date
MSRP $545
See the full B66 Day Date
Prospex Sea The Black Series
SeikoProspex Sea The Black Series
MSRP $765
See the full Prospex Sea The Black Series
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Buy from Seiko ↗
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At a glance

14 of 29 specs differ
Diameter
B66 Day Date44mm
Prospex Sea The Black Series45mm
Power Reserve
B66 Day Date—
Prospex Sea The Black Series41h
Water Resistance
B66 Day Date100m
Prospex Sea The Black Series200m
MSRP
B66 Day Date$545
Prospex Sea The Black Series$765

Full specifications

Case

6 specs
Category
Sport
Diver
Diameter
44mm
45mm
Thickness
—
13.2mm
Lug-to-Lug
51.5mm
47.7mm
Material
Titanium (DLC coated)
Stainless Steel
Water Resistance
100m
200m

Crystal & Dial

4 specs
Crystal
Domed Sapphire
Sapphire
AR Coating
—
Anti-reflective coating on inner surface
Dial Color
Standard
—
Lume
None
LumiBrite on hands, index(es) and bezel

Movement

3 specs
Caliber
—
Seiko 4R36
Power Reserve
0h
41h
Jewels
0
24

Pricing

1 specs
MSRP
$545
$765
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