Watch Almanac
Omega

Speedmaster Moonwatch Professional (sapphire sandwich)

Ref. 310.30.42.50.01.002 · “Sapphire Sandwich”

Case diameter
42 mm
Manufacturer spec
Lug-to-lug
47.5 mm
Manufacturer spec
Thickness
13.2 mm
Manufacturer spec
Lug width
20 mm
Manufacturer spec

Retail price $9,000 (US, Oct 2026)

Ideal fit
Wrist flat: 55.1 mmLug-to-lug: 47.5 mm

How the Speedmaster Moonwatch Professional (sapphire sandwich) wears

Its lugs add only 5.5 mm to the 42 mm case, against 7.1 mm typical across the almanac, so it wears smaller than its diameter suggests.

On our fit model it sits best on wrists from 6.75" to 8" (17.1–20.3 cm); below 6.75" the lugs start to reach the edge of the wrist.

At 13.2 mm thick it is slimmer than 63% of the 24 other chronograph watches we've measured, so it slides under a cuff more easily than most.

Its 20 mm lug width is one of the most common strap sizes; 104 other watches here share it, so aftermarket straps are easy to find.

Will the Speedmaster Moonwatch Professional (sapphire sandwich) fit your wrist?

With a 47.5 mm lug-to-lug, here is how it wears across common wrist sizes. We estimate the flat top of each wrist from its circumference; measure yours for a closer answer in the fit finder.

WristFlat width (est.)Fit
6"47.2 mmLugs overhang
6.5"51.2 mmSnug, lugs near the edge
7"55.1 mmIdeal fit
7.5"59.1 mmIdeal fit
8"63 mmIdeal fit

Specifications

Reference
310.30.42.50.01.002
Collection
Speedmaster
Status
In production
Case material
stainless steel
Crystal
sapphire
Water resistance
50 m
Bezel
black anodised aluminium tachymeter, dot over 90
Dial
black
Strap / bracelet
steel, five links per row, foldover clasp with comfort setting
Weight
138 g
Style
Chronograph

Movement

Caliber
Omega 3861
Type
manual
Power reserve
50 hours
Frequency
21,600 vph (3 Hz)
Accuracy
0/+5 s/day (METAS Master Chronometer)

Takes 20 mm straps. See other 20 mm watches and straps.

More Speedmaster references

Watches that wear the same size

Other watches within 1.5 mm of its lug-to-lug.

Same 20 mm lug width

All 20 mm watches

These take the same straps as the Speedmaster Moonwatch Professional (sapphire sandwich).

Sources