Sinn watch 358 sa pilot rubber based on the classic sinn 356 instrument chronograph the sinn 358 series offers a 42 mm diameter case and features a combination of clarity functionalism and elegance however it is not only the size which distinguishes these chronographs but also the conspicuous domed glass we use sapphire crystal for this and for the transparent back in the 358 sa pilot creating such glasses requires a high level of craftsmanship and represents a specialised skill within th