Side by side
Lum-Tec B66 Day DatevsLongines ULTRA‑CHRON CARBON
The numbers, the dial colors, the calibers — laid out so you can stop flipping between tabs.
At a glance
22 of 29 specs differDiameter
B66 Day Date44mm
ULTRA‑CHRON CARBON43mm
Power Reserve
B66 Day Date40h
ULTRA‑CHRON CARBON52h
Water Resistance
B66 Day Date100m
ULTRA‑CHRON CARBON300m
MSRP
B66 Day Date$545
ULTRA‑CHRON CARBON$5,550
Full specifications
Case
8 specsCategory
Sport
Diver
Diameter
44mm
43mm
Thickness
—
14mm
Lug-to-Lug
51.5mm
48.9mm
Material
Titanium (DLC coated)
Titanium
Finish
Brushed and polished
—
Water Resistance
100m
300m
Caseback
Solid
Screw-down case back
Crystal & Dial
6 specsCrystal
Domed Sapphire
Sapphire
Crystal Shape
Flat
—
AR Coating
Inner
Both sides
Dial Color
Standard
Silver
Indices
Applied
Applied indexes
Lume
None
Super-LumiNova
Movement
7 specsCaliber
—
L836.6
Beat Rate
28,800 vph
36,000 vph
Power Reserve
40h
52h
Jewels
25
0
Hacking
Yes
No
Hand-winding
Yes
No
Complications
None
Hours, minutes, seconds
Pricing
1 specsMSRP
$545
$5,550
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