To create this watch, Sinn built on the extremely popular design of the Sinn 857 UTC but removed the UTC complication - the result is a brand new watch called the Sinn 857 (Non UTC) on strap.
The result is a clear, easy to read dial which resembles the now retired Sinn 657 but in a larger size (43 mm) which is fully Tegimented.
Standard steel used by most watch companies has a hardness of between 200 and 240 HV (Hardness Vickers is a common scale used to measure material hardness). The Tegiment layer on this watch has a hardness of 1,200 Vickers which is six times harder than standard steel.
The Tegiment layer is not a coating consisting of a foreign material, instead the steel itself that has been hardened using a special engineering process that creates a hardened barrier. The base material is a type of stainless steel also used for surgical implants, and the stainless steel resistance to corrosion is even further improved by the Tegiment hardening process.
The case back is nickel free, perfect for those with allergic reactions to case metals. Other features include protection from magnetic fields of up to 80,000 A/m, sapphire crystal with anti-reflective coating on both sides.
Another Sinn engineering feat is the creation of a bezel that is secured by screws. The inlaid aluminum ring featuring numerals and markers is anodized black for optimal legibility, while the triangle reference marker at 12 is applied with special paint for visibility.
The case features a copper sulphate capsule which reacts with moisture to diffuse and absorb humidity in the watch. This capsule may be viewed through a porthole in the left lug, and over time will turn a deep blue as humidity is absorbed. This technology not only provides a more stable environment for the movement, but also helps to prevent fogging of the crystal when going from hot to cold environments or from humid to non-humid conditions (such air conditioned buildings).
Dial is matte black with Arabic numerals and offset date display at 4. The design and layout of this watch make it extremely easy to read in virtually all light conditions.
Sapphire crystal with luminous hands, hour markers and the 12. Watch is water resistant to 20 ATM. Watch is fitted with a black Sinn calf leather strap and tang buckle.
