Speedmaster Moonwatch Professional

Ref. 310.30.42.50.01.001 · “Moonwatch”

Case diameter: 42 mm; Manufacturer spec
Lug-to-lug: 47.5 mm; Manufacturer spec
Thickness: 13.5 mm; Manufacturer spec
Lug width: 20 mm; Manufacturer spec

Retail price $7,800 (US, Oct 2026)

Your wristIdeal fit

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

How the Speedmaster Moonwatch Professional 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 13.5 mm thick it is slimmer than 50% 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 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.

Wrist	Flat width (est.)	Fit
6"	47.2 mm	Lugs overhang
6.5"	51.2 mm	Snug, lugs near the edge
7"	55.1 mm	Ideal fit
7.5"	59.1 mm	Ideal fit
8"	63 mm	Ideal fit

Specifications

Reference: 310.30.42.50.01.001
Collection: Speedmaster
Status: In production
Case material: stainless steel
Crystal: hesalite
Water resistance: 50 m
Bezel: fixed, aluminium tachymeter
Dial: black
Strap / bracelet: steel bracelet
Weight: 134 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.