Which is cheaper, the Lum-Tec B66 Day Date or the Seiko Prospex LX line?

At MSRP the Lum-Tec B66 Day Date is the cheaper of the two at $545, against $6,500 for the Seiko Prospex LX line — a $5,955 gap before any retailer discounting.

Which is bigger, the Lum-Tec B66 Day Date or the Seiko Prospex LX line?

The Seiko Prospex LX line wears larger at 44.8mm versus 44mm for the Lum-Tec B66 Day Date — a 0.8mm difference across the dial.

Which has better water resistance, the Lum-Tec B66 Day Date or the Seiko Prospex LX line?

The Seiko Prospex LX line is rated to 300m versus 100m for the Lum-Tec B66 Day Date.

Which has a longer power reserve, the Lum-Tec B66 Day Date or the Seiko Prospex LX line?

The Seiko Prospex LX line carries a 72-hour power reserve against 40 hours on the Lum-Tec B66 Day Date.

What movement does the Lum-Tec B66 Day Date run compared to the Seiko Prospex LX line?

The Lum-Tec B66 Day Date runs a automatic caliber, while the Seiko Prospex LX line runs a spring drive (5R65).

Side by side

Lum-Tec B66 Day DatevsSeiko Prospex LX line

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

Lum-Tec B66 Day Date

b66-day-date

MSRP $545

Seiko Prospex LX line

snr029j1

MSRP $6,500

At a glance

15 of 29 specs differ

Diameter

B66 Day Date44mm

Prospex LX line44.8mm

Power Reserve

B66 Day Date40h

Prospex LX line72h

Water Resistance

B66 Day Date100m

Prospex LX line300m

MSRP

B66 Day Date$545

Prospex LX line$6,500

Full specifications

Case

6 specs

Crystal & Dial

4 specs

Crystal

Domed Sapphire

Sapphire

AR Coating

Inner

Anti-reflective coating on inner surface

Dial Color

Standard

Black

Lume

None

LumiBrite on hands and index(es)

Movement

4 specs

Caliber

—

5R65

Type

Automatic

Spring Drive

Power Reserve

40h

72h

Jewels

Pricing

1 specs

MSRP

$545

$6,500

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Lum-Tec B66 Day DatevsSeiko Prospex LX line

At a glance

Full specifications

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