Omega Speedmaster Mark 4.5 Professional
Record status
Individual type · partial
Period
mid-1970s
Maker / issuer
OmegaThe Omega Speedmaster Mark 4.5 Professional, reference 176.0012, is an automatic chronograph wristwatch introduced during the mid-1970s. It features a 42mm stainless steel tonneau-shaped case with hooded lugs and radial brushing.
The dial follows a "TV-style" layout with squared-off registers, protected by a hesalite crystal. The watch is powered by the Omega Caliber 1045, an automatic movement derived from Lemania architecture, which includes central chronograph seconds and minute counters, along with a day-date display. The piece is fitted with a stainless steel bracelet and was designed for daily wear with a 48-hour power reserve and 30m water resistance.
This model serves as part of the broader Mark series, representing a shift in Omega's design language during the period of its production.
Evidence at a glance
- Linked sources
- 1
- Photograph views
- 1
- Catalogue references
- 0
Counts describe this entry’s documentation, not authenticity, rarity or completeness. Photographs may show one specimen; check each caption and licence.
Technical characteristics
- Type
- Chronograph
- Maker
- Omega
- Movement
- Caliber 1045
- Reference
- 176.0012
- Case dimensions
- 42mm
- Crystal material
- Hesalite
- Water resistance
- 30m
- Maker / attribution
- Omega
- Date of introduction
- mid-1970s
Design
- Visible features
- • Tonneau-shaped case with radial brushing • Hesalite crystal over the dial • Integrated stainless steel bracelet • Day-date window located at the 3 o'clock position
- Case and Dial Design
- The Mark 4.5 is characterized by a 42mm stainless steel tonneau case, which features hooded lugs and a radial brushing finish. The architecture of the case is described as cushion-shaped and solid. The dial is distinguished by a 'TV-style' layout, which involves the squaring off of the chronograph registers to manage visual balance while maintaining legibility. The dial is shielded by a hesalite crystal, which is the manufacturer's trade term for its specific acrylic material. The overall design language is noted for its utility and presence, intended to function within the context of the 1970s, featuring a solid caseback and being paired with a steel bracelet.
- Movement and Functionality
- The watch utilizes the Omega Caliber 1045, an automatic movement developed from Lemania chronograph architecture. This movement is specifically noted for its inclusion of both a central chronograph seconds hand and a central chronograph minute counter, which are intended to improve the readability of elapsed time measurements. Beyond the chronograph functions, the Caliber 1045 provides a day-date display. The movement is specified as having a 48-hour power reserve, contributing to the utilitarian design goals of the watch during its production period.
- Historical Context and Series
- Part of the Omega Mark series, the 176.0012 is positioned as an experimental model within the brand's larger chronograph lineage. It was produced for a short window starting in the mid-1970s, acting as an alternative to the traditional Speedmaster "Moonwatch" design. The source describes this watch as an example of Omega's effort to update its chronograph design for the decade, moving away from previous iterations to create a more technical and modern aesthetic for the era.
Identification
- Reference
- 176.0012
- Source note
- Facts transcribed from the linked source listing or collection record. Attribution and specifications are source-reported and have not been independently authenticated.
Catalogue references
No catalogue numbers recorded. Numbers are only published once transcribed from a verified edition of a standard catalogue — they are never inferred.
Research required
- Research required: The specific production window is described only as a 'short window'
- Research required: The exact material composition of the gold-colored inner bezel ring is not detailed