Speedmaster Calibre 321 39.7 mm

Having been a part of all six lunar missions, the legendary OMEGA Speedmaster is one of the world’s most iconic timepieces. This model has reprised the famous Calibre 321, which was an important part of the Speedmaster’s original space history.The 39.70 mm case is in stainless steel and is inspired by the same 3rd generation style worn during America’s first spacewalk in 1965. There is also a bezel ring in polished black ceramic [ZrO2] with the tachymeter scale in white enamel.The black step dial features familiar Moonwatch hands, a vintage OMEGA logo, as well as a small seconds sub-dial, 30-minute recorder and 12-hour recorder along with a central chronograph hand. Through the sapphire-crystal caseback, you can see the Calibre 321 inside.

Features
Chronograph: The chronograph function is a mechanism for measuring time intervals. A chronograph watch can therefore be used to time events while displaying the time like any traditional watch.
Small seconds: A hand on a sub-dial which tracks seconds typically it completes a full rotation in one minute.
Tachymeter: A tachymeter watch has a function for measuring speed. It is a chronograph with a graduated dial on which speed can be read in kilometres per hour based on a 1000 metre distance.
Transparent caseback: A transparent caseback - frequently made of sapphire - makes it possible to see the movement inside the watch.

Technical Data
Reference: 311.30.40.30.01.001
Between lugs: 19 mm
Lug‑to‑lug: 48.0 mm
Thickness: 13.7 mm
Case diameter: 39.7 mm
Case: Steel
Dial colour: Black
Crystal: Scratch‑resistant sapphire crystal with anti‑reflective treatment inside
Water resistance: 5 bar (50 metres / 165 feet)
Total product weight (approx.): 128 g
Calibre: Omega 321
Movement Type: Manual‑winding
Power reserve: 55 hours

Bracelet
Material: Steel
Type of Clasp: Foldover clasp