The Sinn 105 St Sa UTC Collection

A new UTC model, the 105 St Sa UTC with dual time functionality on a 24-hour scale, joins Sinn’s Instrument Watch collection in the new sporty Series 105 sub-category. When you read about the launch of GMTs or world timers, most brands try to conjure a glamorous world of first-class travel experiences. Forget about flowery descriptions here; Sinn Spezialuhren does things the German way and its dual time watch is unambiguously referred to as the Sinn 105 St Sa UTC (St stands for steel and Sa for sapphire). Everything about the watch, including the more accurate UTC denomination, reflects the brand’s technical, precision-oriented mindset.

Technology first

Renowned for its robust instrument watches, functionality and precision are the watchwords at Sinn. To differentiate the brand from other instrument watch brands, Sinn has invested heavily in cutting-edge technology – and even created a new industry standard for pilot watches (TESTAF). Like all the brand’s products, the Sinn 105 St Sa UTC model is equipped with insignia Sinn technology. The recently launched Series 105 sub-collection gives Sinn’s hallmark utilitarian style a sportier, more minimalist look. The characteristic solid build of Sinn watches, with angular crown guards and lugs, is very much in place and to date, the burgeoning collection features two models: this UTC model and a simpler three-hand day/date.

The terms GMT and UTC are often interchanged, but there is a crucial difference: GMT stands for Greenwich Mean Time and refers to a time zone, UTC refers to Coordinated Universal Time and is a time standard. UTC is the primary world time standard and is based on International Atomic Time. It’s obvious why this German company went for the more precise appellation.

The case is made of stainless steel, measures 41mm in diameter and has a thickness of 11.9mm. In tune with the sportier spirit of the Series 105, the entire case is bead-blasted. To set up a second time zone (home time, for example), the notched, 24-hour ratcheting bezel can be twisted in either direction to coincide with the bright orange arrow-shaped UTC hand. This means that local time can be adjusted in seconds via the crown. If the wearer prefers though, the orange UTC hand can also be adjusted in the traditional manner via the crown. To facilitate manipulation, the screw-down crown is large and protrudes noticeably from the case.

The bezel can also be used to determine cardinal points when the Sun is visible. By pointing the 12-hour hand towards the Sun (northern hemisphere), the 24-hour hand will be pointing due North.

Two proprietary Sinn technologies are used to make the captive bezel. The surface of the stainless steel case is hardened using TEGIMENT technology, a hardening process that provides highly effective protection against scratches. It is not a coating, but a special process that creates a protective layer. The next step involves the application of a PVD black hard coating. Because it is applied on an already hardened surface, the paint doesn’t crack, flake or produce an eggshell effect as it can do on soft core cases.

Like many Sinn models, the case is rock solid with crown guards and a screw-down crown and caseback. It conforms to the German DIN 8310 standards and is pressure-resistant to 20 bar (equivalent to a water-resistance of 200m).

The essentials

The dial, available in matte black or matte white, is straightforward and extremely easy to consult. The elongated oval-shaped indices, which match the tip of the central seconds hand, are white and filled with luminescent material just like the rounded baton-style hour and minute hands. Picked out in bright orange, the UTC arrow-tipped hand stands out clearly against the matte background for instant readings. The inscription UTC is also orange and placed above the date window at 6 o’clock (background is the same colour as the dial). The dial is protected with an anti-reflective sapphire crystal glass.

Outsourced movement

Sinn uses a Sellita SW330-1, an automatic movement beating at 28,800vph with a power reserve of 42 hours. The screw-fastened caseback has a central aperture with a sapphire crystal glass to view the movement with its industrial decoration including Côtes de Genève on the rotor, perlage and blued screws.

Strap options & price

There are three bracelet/strap options for the Sinn 105 St Sa UTC Collection: a black silicone strap, an integrated two-link bead-blasted stainless steel bracelet, and a host of leather straps in different textures, styles and colours. There is a handy configurator on the brand’s webpage to help you decide.

Prices of the 105 St Sa UTC are as follows: EUR 1,590 (incl. tax) with silicone or leather strap and EUR 1,790 (incl. tax) with solid stainless steel bracelet. Shipping charges outside Germany vary, so please consult Sinn for updated costs.